Carbonylation ligands and their use in the carbonylation of ethylenically unsaturated compounds

Abstract

Novel bidentate ligands of general formula (I) are described. In formula (I), A and B each independently represent a linking group; and R represents a hydrocarbyl aromatic structure. The substituent(s) Y.sup.i on the aromatic structure together have a total number Σt.sub.i of atoms other than hydrogen such that Σt.sub.i is greater than or equal to 4, wherein t.sub.i represents the number of atoms other than hydrogen on a particular substituent Y.sup.i. i ranges from 1 to n; and n is the total number of substituent(s) Y.sup.i. The groups X.sup.1, X.sup.2, X.sup.3 and X.sup.4 are joined via tertiary carbon atoms to the respective atom Q.sup.2 or Q.sup.1. Q.sup.1 and Q.sup.2 each independently represent phosphorus, arsenic, or antimony. A catalyst system and a process for the carbonylation of ethylenically unsaturated compounds utilizing the catalyst system are also described. ##STR00001##

Claims

1. A novel bidentate ligand of general formula (I) ##STR00072## wherein: A and B represent C.sub.0 or a methylene group wherein by C.sub.0 is meant that the group Q.sup.1 or Q.sup.2 is connected directly to the R group and there is no methylene group and in this case the other group cannot be C.sub.0 and must be a methylene group and, therefore, at least one of A and B is a methylene group; R represents a hydrocarbyl aromatic structure or ferrocene structure having at least one aromatic ring to which Q.sup.1 and Q.sup.2 are each linked, via the respective linking group, on two available adjacent cyclic atoms of the at least one aromatic ring and which is substituted with one or more substituent(s) Y.sup.i on one or more further aromatic cyclic atom(s) of R; wherein immediately adjacent cyclic atoms of Ron either side of the said two available adjacent cyclic atoms are not substituted; wherein the substituent(s) Y.sup.i on the aromatic structure together have a total number Σt.sub.i of atoms other than hydrogen such that Σt.sub.i is greater than or equal to 4, wherein t.sub.i represents the number of atoms other than hydrogen on a particular substituent Y.sup.i; wherein the groups X.sup.1, X.sup.2, X.sup.3 and X.sup.4 independently represent univalent radicals of up to 30 atoms having at least one tertiary carbon atom or X.sup.1 and X.sup.2 together, X.sup.3 and X.sup.4 together, or X.sup.1 and X.sup.2 and X.sup.3 and X.sup.4 together form a bivalent radical of up to 40 atoms having at least two tertiary carbon atoms wherein each said univalent or bivalent radical is joined via said at least one or two tertiary carbon atoms respectively to the respective atom Q.sup.1 or Q.sup.2; and wherein Q.sup.1 and Q.sup.2 each independently represent phosphorus, arsenic or antimony; wherein each Y.sup.i independently represents —SR.sup.40R.sup.41R.sup.42; wherein S is selected from Si or; wherein R.sup.40, R.sup.41 and R.sup.42 are independently selected from C.sub.1 to C.sub.10 alkyl or five-to-ten-membered carbocyclic aryl; wherein n is the total number of substituent(s) Y.sup.i; and wherein i ranges from 1 to n.

2. The ligand as claimed in claim 1, wherein the substituents are selected from the group consisting of t-butyl; t-alkyl; 2-phenylprop-2-yl; alkylsilyl; —SiMe.sub.3; alkylphenyl; or phenylalkyl; which groups are unsubstituted or substituted.

3. The ligand as claimed in claim 1, wherein there are two or more said Y′ substituents.

4. The ligand as claimed in claim 3, wherein two or more said substituents combine to form a further ring structure.

5. The ligand as claimed in claim 1, wherein the hydrocarbyl aromatic structure has from 6 up to 30 cyclic atoms.

6. The ligand as claimed in claim 1, wherein the group X.sup.1 represents CR.sup.1(R.sup.2)(R.sup.3), X.sup.2 represents CR.sup.4(R.sup.5)(R.sup.6), X.sup.3 represents CR.sup.7(R.sup.8)(R.sup.9) and X.sup.4 represents CR.sup.10(R.sup.11)(R.sup.12), wherein R.sup.1 to R.sup.12 represent alkyl, aryl or het.

7. The ligand as claimed in claim 6, wherein one or more of the organic groups R.sup.1-R.sup.3, R.sup.4-R.sup.6, R.sup.7-R.sup.9, or R.sup.10-R.sup.12 or, alternatively, R.sup.1-R.sup.6, R.sup.7-R.sup.12, or R.sup.1-R.sup.6 and R.sup.7-R.sup.12 when associated with their respective tertiary carbon atom(s) form composite groups which are at least as sterically hindering as t-butyl(s).

8. The ligand as claimed in claim 1, wherein when cyclic, one or more of X.sup.1, X.sup.2, X.sup.3 or X.sup.4 represent congressyl, norbornyl, 1-norbornadienyl or adamantyl.

9. The ligand as claimed in claim 1, wherein ##STR00073## is an optionally substituted 2-Q.sup.2-tricyclo[3.3.1.1{3,7}]decyl group, or is a ring system of formula 1a ##STR00074## wherein YY.sup.1 represents oxygen, sulfur or N—R.sup.55, wherein R.sup.55 represents hydrogen, alkyl or aryl, wherein R.sup.49 and R.sup.54 are each independently selected from the group consisting of hydrogen, alkyl, or aryl, and wherein R.sup.50, R.sup.51, R.sup.52, and R.sup.53 are each independently selected from the group consisting of alkyl, aryl, or Het, wherein Het is a 4- to 12-membered ring system comprising at least one heteroatom selected from nitrogen, oxygen, and sulfur, optionally substituted.

10. The ligand as claimed in claim 1, wherein ##STR00075## is an optionally substituted 2-Q.sup.1-tricyclo[3.3.1.1{3,7}]decyl group, or is a ring system of formula 1b ##STR00076## wherein YY.sup.2 represents oxygen, sulfur or N—R.sup.55, wherein R.sup.55 represents hydrogen, alkyl or aryl, wherein R.sup.49 and R.sup.54 are each independently selected from the group consisting of hydrogen, alkyl, or aryl, and wherein R.sup.50, R.sup.51, R.sup.52, and R.sup.53 are each independently selected from the group consisting of alkyl, aryl, or Het, wherein Het is a 4- to 12-membered ring system comprising at least one heteroatom selected from nitrogen, oxygen, and sulfur, optionally substituted.

11. A novel bidentate ligand of general formula (I) ##STR00077## wherein: A and B represent Co or a methylene group wherein by C.sub.0 is meant that the group Q.sup.1 or Q.sup.2 is connected directly to the R group and there is no methylene group and in this case the other group cannot be C.sub.0 and must be a methylene group and, therefore, at least one of A and B is a methylene group; R represents a hydrocarbyl aromatic structure or ferrocene structure having at least one aromatic ring to which Q.sup.1 and Q.sup.2 are each linked, via the respective linking group, on two available adjacent cyclic atoms of the at least one aromatic ring and which is substituted with one or more substituent(s) Y.sup.i on one or more further aromatic cyclic atom(s) of R; wherein immediately adjacent cyclic atoms of R on either side of the said two available adjacent cyclic atoms are not substituted; wherein the substituent(s) Y.sup.i on the aromatic structure together have a total number Σt.sub.i of atoms other than hydrogen such that Σt.sub.i is greater than or equal to 4, wherein t.sub.i represents the number of atoms other than hydrogen on a particular substituent Y.sup.i; wherein the groups X.sup.1, X.sup.2, X.sup.3 and X.sup.4 independently represent univalent radicals of up to 30 atoms having at least one tertiary carbon atom or X.sup.1 and X.sup.2 together, X.sup.3 and X.sup.4 together, or X.sup.1 and X.sup.2 and X.sup.3 and X.sup.4 together form a bivalent radical of up to 40 atoms having at least two tertiary carbon atoms wherein each said univalent or bivalent radical is joined via said at least one or two tertiary carbon atoms respectively to the respective atom Q.sup.1 or Q.sup.2; and wherein Q.sup.1 and Q.sup.2 each independently represent phosphorus, arsenic or antimony; wherein each Y.sup.i independently represents —SR.sup.40R.sup.41R.sup.42; wherein S is selected from Si or C; wherein R.sup.40, R.sup.41 and R.sup.42 are independently selected from C.sub.1 to C.sub.10 alkyl or five-to-ten-membered carbocyclic aryl; wherein n is the total number of substituent(s) Y.sup.i; and wherein i ranges from 1 to n, wherein the hydrocarbyl aromatic structure R(Y.sup.i).sub.n is selected from 4-t-alkylbenzene-1,2-diyl, 5-t-alkylbenzene-1,2-diyl, 4,5-di-t-alkylbenzene-1,2-diyl, 4,5-di-t-butyl-benzene-1,2-diyl, 4-t-butylbenzene-1,2-diyl, 5-t-butylbenzene-1,2-diyl, 2-t-alkyl-naphthalene-8,9-diyl, 3-t-alkyl-naphthalene-8,9-diyl, 4-t-alkyl-naphthalene-8,9-diyl, 5-t-alkyl-naphthalene-8,9-diyl, 2,3-di-t-alkyl-naphthalene-8,9-diyl, 2,4-di-t-alkyl-naphthalene-8,9-diyl, 2,5-di-t-alkyl-naphthalene-8,9-diyl, 3,5-di-t-alkyl-naphthalene-8,9-diyl, 4,5-di-t-alkyl-naphthalene-8,9-diyl, 2,3,4-tri-t-alkyl-naphthalene-8,9-diyl, 2,3,5-tri-t-alkyl-naphthalene-8,9-diyl, 2,4,5-tri-t-alkyl-naphthalene-8,9-diyl, 3,4,5-tri-t-alkyl-naphthalene-8,9-diyl, 2,3,4,5-tetra-t-alkyl-naphthalene-8,9-diyl, 1,3-bis(trimethylsilyl)-isobenzofuran-5,6-diyl, 4-(trimethylsilyl)-benzene-1,2-diyl, 4-(2′-phenylprop-2′-yl)-benzene-1,2-diyl, 4-di-t-butyl-methylsilyl-benzene-1,2-diyl, 4-(t-butyldimethylsilyl)-benzene-1,2-diyl, 4-t-butylsilyl-benzene-1,2-diyl, 4-(tri-t-butylsilyl)-benzene-1,2-diyl, 4-(2′-tert-butylprop-2′-yl)benzene-1,2-diyl, 4-(2′,2′,3′,4′,4′-pentamethyl-pent-3′-yl)-benzene-1,2-diyl, 4-t-alkylferrocene-1,2-diyl, 1′-t-alkylferrocene-1,2-diyl, 4,5-di-t-butyl-ferrocene-1,2-diyl, 4-t-butylferrocene-1,2-diyl, 1′-t-butylferrocene-1,2-diyl, 4-(trimethylsilyl)-ferrocene-1,2-diyl, 1′-(trimethylsilyl)-ferrocene-1,2-diyl, 4-(2′-phenylprop-2′-yl)-ferrocene-1,2-diyl, 1′-(2′-phenylprop-2′-yl)-ferrocene-1,2-diyl, 4-di-t-butyl,methylsilyl-ferrocene-1,2-diyl, 1′-di-t-butyl,methylsilyl-ferrocene-1,2-diyl, 4-(t-butyldimethylsilyl)-ferrocene-1,2-diyl, 1′-(t-butyldimethylsilyl)-ferrocene-1,2-diyl, 4-(tri-t-butylsilyl)-ferrocene-1,2-diyl, 1′-(tri-t-butylsilyl)-ferrocene-1,2-diyl, 4-(2′-tert-butylprop-2′-yl)ferrocene-1,2-diyl, 1′-(2′-tert-butylprop-2′-yl)ferrocene-1,2-diyl, 4-(2′,2′,3′,4′,4′ pentamethyl-pent-3′-yl)-ferrocene-1,2-diyl, or 1′-(2′,2′,3′,4′,4′ pentamethyl-pent-3′-yl)-ferrocene-1,2-diyl.

12. The ligand as claimed in claim 11, wherein suitable bidentate ligands are 1,2-bis(di-t-butylphosphinomethyl)-4,5-bis-(trimethylsilyl) benzene; 1,2-bis(di-t-butylphosphinomethyl)-4-(trimethylsilyl)benzene; 1,2-bis(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-4,5-bis-(trimethylsilyl)benzene; 1,2-bis(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-4-(trimethylsilyl)benzene; 1,2-bis(di-adamantylphosphinomethyl)-4,5-bis-(trimethylsilyl)benzene; 1,2-bis(di-adamantylphosphinomethyl)-4-(trimethylsilyl)-benzene; 1-(P,P-adamantyl, t-butylphosphinomethyl)-2-(di-t-butylphosphinomethyl)-4,5-bis-(trimethylsilyl)benzene; 1-(P,P-adamantyl, t-butylphosphinomethyl)-2-(di-t-butylphosphinomethyl)-4-(trimethylsilyl)benzene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(di-t-butylphosphinomethyl)-4,5-bis-(trimethylsilyl)benzene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(di-t-butylphosphinomethyl)-4-(trimethylsilyl)-benzene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(diadamantylphosphinomethyl)-4,5-bis-(trimethylsilyl)-benzene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(diadamantylphosphinomethyl)-4-(trimethylsilyl) benzene; 1-(di-t-butylphosphinomethyl)-2-(diadamantylphosphinomethyl)-4,5-bis-(trimethylsilyl) benzene; 1-(di-t-butylphosphinomethyl)-2-(diadamantylphosphinomethyl)-4-(trimethylsilyl) benzene; 1,2-bis(2-phosphinomethyl-1,3,5-trimethyl-6,9, 10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-4,5-bis-(trimethylsilyl)benzene; 1,2-bis(2-phosphinomethyl-1,3,5-trimethyl-6,9, 10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-4-(trimethylsilyl)benzene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(di-t-butylphosphinomethyl)-4,5-bis-(trimethylsilyl)benzene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(di-t-butylphosphinomethyl)-4-(trimethylsilyl) benzene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(diadamantylphosphinomethyl)-4,5-bis-(trimethylsilyl)benzene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(diadamantylphosphinomethyl)-4-(trimethylsilyl)benzene; 1,2-bis-perfluoro(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxatricyclo {3.3.1.1[3.7]}-decyl)-4,5-bis-(trimethylsilyl)benzene; 1,2-bis-perfluoro(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-4-(trimethylsilyl)benzene; 1,2-bis-(2-phosphinomethyl-1,3,5,7-tetra(trifluoro-methyl)-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-4,5-bis-(trimethylsilyl) benzene; 1,2-bis-(2-phosphinomethyl-1,3,5,7-tetra(trifluoro-methyl)-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-4-(trimethylsilyl)benzene; 1,2-bis(di-t-butylphosphinomethyl)-4,5-di-(2′phenylprop-2′-yl)benzene; 1,2-bis(di-t-butylphosphinomethyl)-4-(2′-phenylprop-2′-yl)benzene; 1,2-bis(di-t-butylphosphinomethyl)-4,5-di-t-butylbenzene; 1,2-bis(di-t-butylphosphinomethyl)-4-t-butylbenzene; 1,2-bis(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-4,5-di-(2′-phenylprop-2′-yl)benzene; 1,2-bis(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-4-2′-phenylprop-2′yl benzene; 1,2-bis(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-4,5-(di-t-butyl)benzene; 1,2-bis(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-4-t-butylbenzene; 1,2-bis(di-adamantylphosphinomethyl)-4,5-di-(2′phenylprop-2′-yl)benzene; 1,2-bis(di-adamantylphosphinomethyl)-4-(2′-phenylprop-2′-yl) benzene; 1,2-bis(di-adamantylphosphinomethyl)-4,5-di-t-butylbenzene; 1,2-bis(di-adamantylphosphinomethyl)-4-t-butyl benzene; 1-(P,P-adamantyl, t-butyl phosphinomethyl)-2-(di-t-butylphosphinomethyl)-4,5-di-(2′phenylprop-2′-yl)benzene; 1-(P,P-adamantyl, t-butyl phosphinomethyl)-2-(di-t-butylphosphinomethyl)-4-(2′-phenylprop-2′-yl)benzene; 1-(P,P-adamantyl, t-butyl phosphinomethyl)-2-(di-t-butylphosphinomethyl)-4,5-di-t-butylbenzene; 1-(P,P-adamantyl, t-butyl phosphinomethyl)-2-(di-t-butylphosphinomethyl)-4-t-butylbenzene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(di-t-butylphosphinomethyl)-4,5-di-(2′phenylprop-2′-yl)benzene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(di-t-butylphosphinomethyl)-4-(2′-phenylprop-2′-yl) benzene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(di-t-butylphosphinomethyl)-4,5-di-t-butylbenzene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(di-t-butylphosphinomethyl)-44-butylbenzene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(diadamantylphosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)benzene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(diadamantylphosphinomethyl)-4-(2′-phenylprop-2′-yl)benzene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(diadamantylphosphinomethyl)-4,5-(di-t-butyl)benzene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(diadamantylphosphinomethyl)-4-t-butylbenzene; 1-(di-t-butylphosphinomethyl)-2-(diadamantylphosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl) benzene; 1-(di-t-butylphosphinomethyl)-2-(diadamantylphosphinomethyl)-4-(2′-phenylprop-2′-yl)benzene; 1-(di-t-butylphosphinomethyl)-2-(diadamantylphosphinomethyl)-4,5-(di-t-butyl)benzene; 1-(di-t-butylphosphinomethyl)-2-(diadamantylphosphinomethyl)-44-butylbenzene; 1,2-bis(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-4,5-di-(2′-phenylprop-2′-yl)benzene; 1,2-bis(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-4-(2′-phenylprop-2′-yl) benzene; 1,2-bis(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-4,5-(di-t-butyl)benzene; 1,2-bis(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-4-t-butylbenzene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9, 10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(di-t-butylphosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)benzene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(di-t-butylphosphinomethyl)-4-(2′-phenylprop-2′-yl)benzene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(di-t-butylphosphinomethyl)-4,5-(di-t-butyl)benzene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(di-t-butylphosphinomethyl)-4-t-butylbenzene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(diadamantylphosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)benzene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(diadamantylphosphinomethyl)-4-(2′-phenylprop-2′-yl)benzene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(diadamantylphosphinomethyl)-4,5-(di-t-butyl)benzene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(diadamantylphosphinomethyl)-4-t-butylbenzene; 1,2-bis-perfluoro(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxatricyclo {3.3.1.1[3.7]}-decyl)-4,5-di-(2′-phenylprop-2′-yl)benzene; 1,2-bis-perfluoro(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-4-(2′-phenylprop-2′-yl)benzene; 1,2-bis-perfluoro(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxatricyclo {3.3.1.1[3.7]}-decyl)-4,5-(di-t-butyl) benzene; 1,2-bis-perfluoro(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-4-t-butyl benzene; 1,2-bis-(2-phosphinomethyl-1,3,5,7-tetra(trifluoro-methyl)-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-4,5-di-(2′-phenylprop-2′-yl) benzene; 1,2-bis-(2-phosphinomethyl-1,3,5,7tetra(trifluoro-methyl)-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-4-(2′-phenylprop-2′-yl)benzene; 1,2-bis-(2-phosphinomethyl-1,3,5,7-tetra(trifluoro-methyl)-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-4,5-(di-t-butyl) benzene; 1,2-bis-(2-phosphinomethyl-1,3,5,7-tetra(trifluoro-methyl)-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-4-t-butyl benzene; 1,2-bis(di-t-butylphosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene; 1,2-bis(di-t-butylphosphinomethyl)-4-(trimethylsilyl)ferrocene; 1,2-bis(di-t-butylphosphinomethyl)-1′-(trimethylsilyl)ferrocene; 1,2-bis(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-4,5-bis-(trimethylsilyl)ferrocene; 1,2-bis(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-4-(trimethylsilyl)ferrocene; 1,2-bis(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-1′-(trimethylsilyl)ferrocene; 1,2-bis(di-adamantylphosphinomethyl)-4,5 bis-(trimethylsilyl)ferrocene; 1,2-bis(di-adamantylphosphinomethyl)-4-(trimethylsilyl)ferrocene; 1,2-bis(di-adamantylphosphinomethyl)-1′-(trimethylsilyl)ferrocene; 1-(P,P-adamantyl, t-butylphosphinomethyl)-2-(di-t-butylphosphinomethyl)-4-(trimethylsilyl)ferrocene; 1-(P,P-adamantyl, t-butylphosphinomethyl)-2-(di-t-butylphosphinomethyl)-1′-(trimethylsilyl)ferrocene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(di-t-butylphosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(di-t-butylphosphinomethyl)-4-(trimethylsilyl) ferrocene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(di-t-butylphosphinomethyl)-1′-(trimethylsilyl) ferrocene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(diadamantylphosphinomethyl)-4,5-bis-(trimethylsilyl) ferrocene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(diadamantylphosphinomethyl)-4-(trimethylsilyl)ferrocene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(diadamantylphosphinomethyl)-1′-(trimethylsilyl)ferrocene; 1-(di-t-butylphosphinomethyl)-2-(diadamantylphosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene; 1-(di-t-butylphosphinomethyl)-2-(diadamantylphosphinomethyl)-4-(trimethylsilyl)ferrocene; 1-(di-t-butylphosphinomethyl)-2-(diadamantylphosphinomethyl)-1′-(trimethylsilyl)ferrocene; 1,2-bis(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-4,5-bis-(trimethylsilyl)ferrocene; 1,2-bis(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-4-(trimethylsilyl)ferrocene; 1,2-bis(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-1′-(trimethylsilyl)ferrocene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(di-t-butylphosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(di-t-butylphosphinomethyl)-4-(trimethylsilyl) ferrocene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(di-t-butylphosphinomethyl)-1′-(trimethylsilyl) ferrocene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(diadamantylphosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(diadamantylphosphinomethyl)-4-(trimethylsilyl)ferrocene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(diadamantylphosphinomethyl)-1′-(trimethylsilyl)ferrocene; 1,2-bis-perfluoro(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxatricyclo {3.3.1.1[3.7]}-decyl)-4,5-bis-(trimethylsilyl)ferrocene; 1,2-bis-perfluoro(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-4-(trimethylsilyl)ferrocene; 1,2-bis-perfluoro(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)1′-(trimethylsilyl)ferrocene; 1,2-bis-(2-phosphinomethyl-1,3,5,7-tetra(trifluoro-methyl)-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-4,5-bis-(trimethylsilyl)ferrocene; 1,2-bis-(2-phosphinomethyl-1,3,5,7-tetra(trifluoro-methyl)-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-4-(trimethylsilyl)ferrocene; 1,2-bis-(2-phosphinomethyl-1,3,5,7-tetra(trifluoro-methyl)-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-1′-(trimethylsilyl)ferrocene; 1,2-bis(di-t-butylphosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene; 1,2-bis(di-t-butylphosphinomethyl)-1′-(2′-phenylprop-2′-yl)ferrocene; 1,2-bis(di-t-butylphosphinomethyl)-4,5-di-t-butylferrocene; 1,2-bis(di-t-butylphosphinomethyl)-4-t-butylferrocene; 1,2-bis(di-t-butylphosphinomethyl)-1′-t-butylferrocene; 1,2-bis(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-4-(2′-phenylprop-2′-yl)ferrocene; 1,2-bis(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-1′-(2′-phenylprop-2′-yl)ferrocene; 1,2-bis(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-4,5-(di-t-butyl)ferrocene; 1,2-bis(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-4-t-butylferrocene; 1,2-bis(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-1′-t-butylferrocene; 1,2-bis(di-adamantylphosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene; 1,2-bis(di-adamantylphosphinomethyl)-1′-(2′-phenylprop-2′-yl) ferrocene; 1,2-bis(di-adamantylphosphinomethyl)-4,5-(di-t-butyl)ferrocene; 1,2-bis(di-adamantylphosphinomethyl)-4-t-butylferrocene; 1,2-bis(di-adamantylphosphinomethyl)-1′-t-butylferrocene; 1-(P,P-adamantyl, t-butylphosphinomethyl)-2-(di-t-butylphosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene; 1-(P,P-adamantyl, t-butylphosphinomethyl)-2-(di-t-butylphosphinomethyl)-1′-(2′-phenylprop-2′-yl)ferrocene; 1-(P,P-adamantyl, t-butyl phosphinomethyl)-2-(di-t-butylphosphinomethyl)-4,5-(di-t-butyl)ferrocene; 1-(P,P-adamantyl, t-butylphosphinomethyl)-2-(di-t-butylphosphinomethyl)-4-t-butylferrocene; 1-(P,P-adamantyl, t-butylphosphinomethyl)-2-(di-t-butylphosphinomethyl)-1′-t-butylferrocene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(di-t-butylphosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(di-t-butylphosphinomethyl)-1′-(2′-phenylprop-2′-yl)ferrocene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(di-t-butylphosphinomethyl)-4,5-(di-t-butyl)ferrocene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(di-t-butylphosphinomethyl)-44-butylferrocene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(di-t-butylphosphinomethyl)-1′-t-butylferrocene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(diadamantylphosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(diadamantylphosphinomethyl)-1′ (2′-phenylprop-2′-yl)ferrocene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(diadamantylphosphinomethyl)-4,5-(di-t-butyl)ferrocene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(diadamantylphosphinomethyl)-44-butylferrocene; 1-(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxa-adamantyl)-2-(diadamantylphosphinomethyl)-1′-t-butylferrocene; 1-(di-t-butylphosphinomethyl)-2-(diadamantylphosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene; 1-(di-t-butylphosphinomethyl)-2-(diadamantylphosphinomethyl)-1′-(2′-phenylprop-2′-yl)ferrocene; 1-(di-t-butylphosphinomethyl)-2-(diadamantylphosphinomethyl)-4,5-(di-t-butyl)ferrocene; 1-(di-t-butylphosphinomethyl)-2-(diadamantylphosphinomethyl)-44-butylferrocene; 1-(di-t-butylphosphinomethyl)-2-(diadamantylphosphinomethyl)-1′-t-butylferrocene; 1,2-bis(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-4-(2′-phenylprop-2′-yl) ferrocene; 1,2-bis(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-1′-(2′-phenylprop-2′-yl) ferrocene; 1,2-bis(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-4,5-(di-t-butyl)ferrocene; 1,2-bis(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-4-t-butylferrocene; 1,2-bis(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-1′-t-butylferrocene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(di-t-butylphosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(di-t-butylphosphinomethyl)-1′-(2′-phenylprop-2′-yl)ferrocene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(di-t-butylphosphinomethyl)-4,5-(di-t-butyl)ferrocene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(di-t-butylphosphinomethyl)-4-t-butylferrocene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(di-t-butylphosphinomethyl)-1′-t-butylferrocene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(diadamantylphosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(diadamantylphosphinomethyl)-1′-(2′-phenylprop-2′-yl)ferrocene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(diadamantylphosphinomethyl)-4,5-(di-t-butyl)ferrocene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(diadamantylphosphinomethyl)-4-t-butylferrocene; 1-(2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl)-2-(diadamantylphosphinomethyl)-1′-t-butylferrocene; 1,2-bis-perfluoro(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-4-(2′-phenylprop-2′-yl)ferrocene; 1,2-bis-perfluoro(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-1′-(2′-phenylprop-2′-yl) ferrocene; 1,2-bis-perfluoro(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxatricyclo {3.3.1.1[3.7]}-decyl)-4,5-(di-t-butyl)ferrocene; 1,2-bis-perfluoro(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-4-t-butylferrocene; 1,2-bis-perfluoro(2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-1′-t-butylferrocene; 1,2-bis-(2-phosphinomethyl-1,3,5,7-tetra(trifluoromethyl)-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-4-(2′-phenylprop-2′-yl)ferrocene; 1,2-bis-(2-phosphinomethyl-1,3,5,7-tetra(trifluoromethyl)-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-1′-(2′-phenylprop-2′-yl)ferrocene; 1,2-bis-(2-phosphinomethyl-1,3,5,7-tetra(trifluoromethyl)-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-4,5-(di-t-butyl)ferrocene; 1,2-bis-(2-phosphinomethyl-1,3,5,7-tetra(trifluoromethyl)-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-4-t-butylferrocene; 1,2-bis-(2-phosphinomethyl-1,3,5,7-tetra(trifluoromethyl)-6,9,10-trioxatricyclo {3.3.1.1[3.7]}decyl)-1′-t-butylferrocene or any of the above ligands wherein one of the methylene groups representing group A or group B is removed so that one of the respective phosphorus atoms is joined directly to the ferrocene or benzene ring representing group R thus forming a C.sub.3 bridge connecting the two phosphorus atoms representing Q.sub.1 and Q.sub.2.

13. The bidentate ligand according to claim 11, wherein the ligands of formula I are selected from: ##STR00078## 1,2-bis(di-tert-butylphospinomethyl)-1′-trimethylsilyl ferrocene ##STR00079## 1,2-bis(di-tert-butylphospinomethyl)-1′-tert-butyl ferrocene ##STR00080## 1,2-bis(di-tert-butylphospinomethyl)-4-trimethylsilyl ferrocene ##STR00081## 1,2-bis(di-tert-butyl(phosphinomethyl))-4-trimethylsilyl benzene ##STR00082## 1,2-bis(di-tert-butyl(phosphinomethyl))-4-(tert-butyldimethylsilyl)benzene ##STR00083## 1,2-bis(di-tert-butyl(phosphinomethyl))-4,5-bis(trimethylsilyl)benzene ##STR00084## 1,2-bis(di-tert-butyl(phosphinomethyl))-4-tert-butyl benzene ##STR00085## 1,2-bis(di-tert-butyl(phosphinomethyl))-4,5-di-tert-butyl benzene ##STR00086## 1,2-bis(di-tert-butyl(phosphinomethyl))-4-(tri-tert-butylmethyl)benzene ##STR00087## 1,2-bis(di-tert-butyl(phosphinomethyl))-4-(tri-tert-butylsilyl)benzene ##STR00088## 1,2-bis(di-tert-butyl(phosphinomethyl))-4-(2′-phenylprop-2′-yl)benzene ##STR00089## 4-(1-{3,4-Bis-[(di-tert-butyl-phosphanyl)-methyl]-phenyl}-1-methyl-ethyl)-benzoyl chloride ##STR00090## 1,2-bis(di-tert-butyl(phosphinomethyl))-4-tertbutyl-5-(2′-tertbutyl-4′,5′-bis(di-tert-butyl(phosphinomethyl))phenyl)benzene; or selected from any one of the above structures wherein one or more of the X.sup.1-X.sup.4 tertiary carbon bearing groups, t-butyl, attached to the Q.sup.1 or Q.sup.2 group or Q.sup.1 and Q.sup.2 group phosphorus is replaced by a suitable alternative selected from adamantyl, 1,3 dimethyl adamantyl, congressyl, norbornyl or 1-norbornodienyl, or X.sup.1 and X.sup.2 together, X.sup.3 and X.sup.4 together or X.sup.1 and X.sup.2 and X.sup.3 and X.sup.4 together form together with the phosphorus a 2-phospha-tricyclo[3.3.1.1{3,7}]decyl group; or selected from any one of the above structures or alternative structures wherein one of the methylene linking groups representing A or B in formula I is removed so that the respective phosphorus atom is attached directly to the aromatic ring representing R and so that a C.sub.3 bridge connects two phosphorus atoms representing Q.sub.1 and Q.sub.2 in the example structures.

14. A process for the carbonylation of ethylenically unsaturated compounds comprising reacting said compound with carbon monoxide in the presence of a source of hydroxyl groups and of a catalyst system, the catalyst system obtainable by combining: (a) palladium or a compound thereof: and (b) a bidentate ligand of general formula (I) ##STR00091## wherein: A and B represent C.sub.0 or a methylene group wherein by C.sub.0 is meant that the group Q.sup.1 or Q.sup.2 is connected directly to the R group and there is no methylene group and in this case the other group cannot be C.sub.0 and must be a methylene group and, therefore, at least one of A and B is a methylene group; R represents a hydrocarbyl aromatic structure or ferrocene having at least one aromatic ring to which Q.sup.1 and Q.sup.2 are each linked, via the respective linking group when the latter is present, on two available adjacent cyclic atoms of the at least one aromatic ring and which is substituted with one or more substituent(s) Y.sup.i on one or more further aromatic cyclic atom(s) of R; wherein immediately adjacent cyclic atoms of R on either side of the said two available adjacent cyclic atoms are not substituted; wherein the substituent(s) Y.sup.i on the aromatic structure together have a total number Σt.sub.i of atoms other than hydrogen such that Σt.sub.i is greater than or equal to 4, wherein t.sub.i represents the number of atoms other than hydrogen on a particular substituent Y.sup.i; wherein the groups X.sup.1, X.sup.2, X.sup.3 and X.sup.4 independently represent univalent radicals of up to 30 atoms having at least one tertiary carbon atom or X.sup.1 and X.sup.2 together, X.sup.3 and X.sup.4 together or X.sup.1 and X.sup.2 and X.sup.3 and X.sup.4 together form a bivalent radical of up to 40 atoms having at least two tertiary carbon atoms wherein each said univalent or bivalent radical is joined via said at least one or two tertiary carbon atoms respectively to the respective atom Q.sup.1 or Q.sup.2; and wherein Q.sup.1 and Q.sup.2 each independently represent phosphorus, arsenic or antimony; wherein each Y.sup.i independently represents —SR.sup.40R.sup.41R.sup.42; wherein S is selected from Si or C; wherein R.sup.40, R.sup.41 and R.sup.42 are independently selected from C.sub.1 to C.sub.10 alkyl or five-to-ten-membered carbocyclic aryl wherein n is the total number of substituent(s) Y.sup.i; wherein i ranges from 1 to n; and, optionally, a source of anions.

15. The process as claimed in claim 14, wherein the ethylenically unsaturated compounds are ethylenically unsaturated compounds having from 2 to 50 carbon atoms per molecule, or mixtures thereof.

16. The process as claimed in claim 2, wherein the ethylenically unsaturated compounds are selected from acetylene, methyl acetylene, propyl acetylene, 1,3-butadiene, ethylene, propylene, butylene, isobutylene, pentenes, pentene nitriles, alkyl pentenoates such as methyl 3-pentenoates, pentene acids (such as 2- and 3-pentenoic acid), heptenes, vinyl esters such as vinyl acetate, octenes, dodecenes.

17. A catalyst system obtainable by combining (a) palladium or a compound thereof: and (b) a bidentate ligand of general formula (I) ##STR00092## wherein: A and B represent Co or a methylene group wherein by Co is meant that the group Q.sup.1 or Q.sup.2 is connected directly to the R group and there is no methylene group and in this case the other group cannot be Co and must be a methylene group and, therefore, at least one of A and B is a methylene group; R represents a hydrocarbyl aromatic structure or ferrocene structure having at least one aromatic ring to which Q.sup.1 and Q.sup.2 are each linked, via the respective linking group, on two available adjacent cyclic atoms of the at least one aromatic ring and which is substituted with one or more substituent(s) Y.sup.i on one or more further aromatic cyclic atom(s) of R; wherein immediately adjacent cyclic atoms of R on either side of the said two available adjacent cyclic atoms are not substituted; wherein the substituent(s) Y.sup.i on the aromatic structure together have a total of atoms other than hydrogen such that Σt.sub.i is greater than or equal to 4, wherein t.sub.i represents the number of atoms other than hydrogen on a particular substituent Y.sup.i; wherein the groups X.sup.1, X.sup.2, X.sup.3 and X.sup.4 independently represent univalent radicals of up to 30 atoms having at least one tertiary carbon atom or X.sup.1 and X.sup.2 together, X.sup.3 and X.sup.4 together or X.sup.1 and X.sup.2 and X.sup.3 and X.sup.4 together form a bivalent radical of up to 40 atoms having at least two tertiary carbon atoms wherein each said univalent or bivalent radical is joined via said at least one or two tertiary carbon atoms respectively to the respective atom Q.sup.1 or Q.sup.2; and wherein Q.sup.1 and Q.sup.2 each independently represent phosphorus, arsenic or antimony; wherein each Y.sup.i independently represents —SR.sup.40R.sup.41R.sup.42; wherein S is selected from Si or C; wherein R.sup.40, R.sup.41 and R.sup.42 are independently selected from C.sub.1 to C.sub.10 alkyl or five-to-ten-membered carbocyclic aryl; wherein n is the total number of substituent(s) Y.sup.i; and wherein i ranges from 1 to n; and, optionally, a source of anions.

Description

SYNTHESIS EXAMPLES

(1) Preparation of Example Ligands of the Invention is as Follows

(2) Compound 1

Synthesis of 1,2-bis(di-tert-butylphosphinomethyl)-4trimethylsilyl benzene

(3) Part (I)

Synthesis of 4-trimethylsilyl-o-xylene

(4) Magnesium ribbon (2.91 g, 115.41 mmol) was added to a schlenk flask. To this was added a few (3-4) crystals of iodine. THF (150 ml) was then added to give an orange/yellow solution. 4-bromo-o-xylene (19.41 g, 104.91 mmol) was diluted with THF (80 ml) and then added slowly over one hour to the magnesium suspension, the reaction flask being placed in a warm (50° C.) water bath for the duration of the reaction. This gave a dark orange/brown solution with some insoluble magnesium. This solution was then heated to 85° C. for one hour. The solution was then allowed to cool to room temperature before being cannula transferred into a clean schlenk away for the unreacted magnesium. The THF solution was then cooled to −78° C. before trimethylsilyl chloride (13.41 ml, 104.91 mmol) was added by syringe. The resultant solution was then allowed to stir at −78° C. for thirty minutes before being allowed to warm to room temperature. The resultant solution was then stirred at room temperature overnight. The solution was quenched by the addition of water (100 ml). Ether (100 ml) was then added and the biphasic mixture separated. The aqueous layer was washed with ether (100 ml) and the organic extracts combined. The organic extracts were then dried over sodium sulphate before being filtered. The filtrate was then dried under vacuum to give a colourless oil. Yield=14.47 g, 77%.

(5) Part (II)

(6) The 4-trimethylsilyl-o-xylene (5.00 g, 28.1 mmol) (prepared in Part (I) was diluted with heptane (100 ml) and to this was added NaOBu.sup.t (8.1 g, 84.3 mmol), TMEDA (12.6 ml, 84.3 mmol) and Bu.sup.nLi (2.5M in hexanes, 33.7 ml, 84.3 mmol). The butyl lithium was added dropwise and gave an immediate colour change from colourless to yellow to orange to dark red. The solution was then heated to 65° C. for three hours. This gave a brown/orange suspension. The suspension was cooled to room temperature and the supernatant liquid removed by cannula. The brown precipitate residue was then washed with pentane (100 ml). The pentane washings were then removed by cannula. The solid residue was then suspended in pentane (100 ml) and then cooled in a cold water bath. Bu.sup.t.sub.2PCl (7.5 ml, 39.3 mmol) was then added dropwise to the suspension. The resultant suspension was then stirred for three hours and stood overnight. Water (100 ml) was degassed with nitrogen gas for 30 minutes and then added to the suspension. This gave a biphasic solution. The upper (organic phase) was diluted with pentane (100 ml) and the organic phase removed by cannula into a clean schlenk flask. The pentane extract was then dried over sodium sulphate and transferred into a clean schlenk flask by cannula. The solvent was then removed under vacuum to give orange oil. To this was added methanol (100 ml) which give a biphasic solution. This was then heated to reflux (70° C.) which gave a pale yellow solution and some colourless insoluble material. The solution was then cooled to room temperature and filtered into a clean schlenk flask. The solution was then placed in the freezer at −20° C. overnight. This gave the deposition of an off-white solid. The remaining methanol solution was then removed by cannula and the solid dried under vacuum. The solid was isolated in the glovebox. Yield=4.70 g, 36%. 92% pure. .sup.31P {.sup.1H} NMR (CDCl.sub.3, 161.9 MHz, 5); 27.3 (s), 26.1 (s) ppm.

(7) Compound 2

Synthesis of 1,2-bis(di-tert-butylphosphinomethyl)-4-tert-butyl-benzene

(8) The 4-tert-butyl-o-xylene (4.55 g, 28.1 mmol) (Aldrich) was diluted with heptane (100 ml) and to this was added NaOBu.sup.t (8.1 g, 84.3 mmol), TMEDA (12.6 ml, 84.3 mmol) and Bu.sup.nLi (2.5M in hexanes, 33.7 ml, 84.3 mmol). The butyl lithium was added dropwise and gave an immediate colour change from colourless to yellow to orange to dark red. The solution was then heated to 65° C. for three hours. This gave a brown/orange suspension. The suspension was cooled to room temperature and the supernatant liquid removed by cannula the brown precipitate residue was then washed with pentane (100 ml. The pentane washings were then removed by cannula. The solid residue was then suspended in pentane (100 ml) and then cooled in a cold water bath. Bu.sup.t.sub.2PCl (7.5 ml, 39.3 mmol) was then added dropwise to the suspension. The resultant suspension was then stirred for three hours and stood overnight. Water (100 ml) was degassed with nitrogen gas for 30 minutes and then added to the suspension. This gave a biphasic solution. The upper (organic phase) was diluted with pentane (100 ml) and the organic phase removed by cannula into a clean schlenk flask. The pentane extract was then dried over sodium sulphate and transferred into a clean schlenk flask by cannula. The solvent was then removed under vacuum to give orange oil. To this was added methanol (100 ml) which give a biphasic solution. This was then heated to reflux (70° C.) which gave a pale yellow solution and some colourless insoluble material. The solution was then cooled to room temperature and filtered into a clean schlenk flask. The solution was then placed in the freezer at −20° C. overnight. This gave the deposition of an off-white solid. The remaining methanol solution was then removed by cannula and the solid dried under vacuum. The solid was isolated in the glovebox. Yield=4.20 g, 33%. 95% pure. .sup.31P {.sup.1H} NMR (CDCl.sub.3, 161.9 MHz, 5); 27.1 (s), 26.3 (s) ppm.

(9) Compound 3

Synthesis of 1,2-bis(di-tert-butylphosphinomethyl)-1′-(triphenylsilyl) ferrocene

(10) Part (I)

Preparation of 1-bromo-1′-triphenylsilyl ferrocene

(11) ##STR00038##

(12) To 1,1′-dibromoferrocene (10.14 g, 29.49 mmol) in dry THF (200 ml) cooled to −78° C. (dry ice/acetone bath) was added n-butyllithium (12.56 ml, 28.02 mmol, 0.95 eq) and the reaction was stirred under N.sub.2 for 30 min. Chlorotriphenylsilane (8.26 g, 28.02 mmol, 0.95 eq) dissolved in the minimum amount of dry THF was then added dropwise and the solution was then allowed to warm up to room temperature and further stirred for twelve hours resulting in a red solution.

(13) The reaction was then quenched with water, and stirred for a further fifteen minutes. The ethereal layer, containing product was separated and the aqueous layer was further extracted several times with diethyl ether. The combined ether fractions were dried over magnesium sulphate and filtered through celite. The ether solvent was removed by rotary evaporator (resulting in red oil). The product was purified by column chromatography. Starting material was removed with petrol and the product was then obtained with petrol/10% Et.sub.2O as an orange band. The resulting oil was finally dried under vacuum leaving pure product as orange crystals: (11.09 g, 72% yield).

(14) Part (II)

Preparation of 1-dimethylaminomethyl-1′-triphenylsilyl ferrocene

(15) ##STR00039##

(16) To 1-bromo-1′-triphenylsilyl ferrocene (8 g, 15.29 mmol) in dry diethyl ether (100 ml) was added n-butyllithium (6.73 ml, 16.82 mmol, 1.1 eq) and the reaction was stirred under N.sub.2 for 1 hour at room temperature. Dry THF (100 ml) was then added and solution was then cooled to −78° C. (dry ice/acetone bath) and quenched with Eschenmoser's salt (3.11 g, 16.82 mmol, 1.1 eq). The solution was then allowed to warm up to room temperature and further stirred for twelve hours resulting in a yellow solution.

(17) The reaction was then quenched with water, and stirred for a further fifteen minutes. The ethereal layer, containing product was separated and the aqueous layer was further extracted several times with diethyl ether. The combined ether fractions were dried over magnesium sulphate and filtered through celite. The ether solvent was removed by rotary evaporator (resulting in red oil). The product was purified by column chromatography. Starting material was removed with petrol (10% Et.sub.2O) and the product was then obtained with 1:1 petrol/Et.sub.2O (5% triethylamine). The resulting red oil was finally dried under vacuum leaving pure product as red/orange crystals: (3 g, 39% yield).

(18) Part (III)

Preparation of 1,2-bis-dimethylaminomethyl-1′-triphenylsilyl ferrocene

(19) ##STR00040##

(20) To 1-dimethylaminomethyl-1′-triphenylsilyl ferrocene (2.66 g, 5.30 mmol) in dry diethyl ether (100 ml) was added n-butyllithium (2.55 ml, 6.36 mmol, 1.2 eq) and the reaction was stirred under N.sub.2 for 1 hour at room temperature. Dry THF (100 ml) was then added and solution was then cooled to −78° C. (dry ice/acetone bath) and quenched with Eschenmoser's salt (1.08 g, 5.83 mmol, 1.1 eq). The solution was then allowed to warm up to room temperature and further stirred for twelve hours resulting in an orange solution.

(21) The reaction was then quenched with water, and stirred for a further fifteen minutes. The ethereal layer, containing product was separated and the aqueous layer was further extracted several times with diethyl ether. The combined ether fractions were dried over magnesium sulphate and filtered through celite. The ether solvent was removed by rotary evaporator (resulting in red oil). The product was purified by column chromatography. Starting material was removed with petrol (10% Et.sub.2O) and the product was then obtained with 1:1 petrol/Et.sub.2O (5% triethylamine). The resulting red oil was finally dried under vacuum: (2.94 g, 99% yield).

(22) Part (IV)

1,2-bis(dimethylaminomethyl)-1′-(triphenylsilyl)ferrocene

(23) (5.15 g, 9.23 mmol) and di-tert-butylphosphine (4.00 g, 27.40 mmol) were added together in a schlenk flask. To this was added acetic acid:acetic anhydride (100 ml: 10 ml) which had been degassed with nitrogen for 30 minutes. The resultant suspension was then heated to 130° C. for five hours. The solution was then cooled to room temperature and the solvent removed under vacuum. The residue was suspended in methanol (50 ml) and stirred for 20 minutes. The methanol was then removed under vacuum. The residue was then suspended in ethanol (50 ml) and the ethanol suspension heated to reflux. This gave a red solution which was then allowed to cool to room temperature before being placed in the freezer overnight at −20° C. This gave the precipitation of an red-orange solid. The mother liquor was cannula transferred into a clean schlenk and the residue dried under vacuum. This solid was then isolated in the glovebox. Yield=2.8 g, 40%. 95% pure. .sup.31P {.sup.1H} NMR (CDCl.sub.3, 161.9 MHz, 5); 23.5 ppm

(24) Compound 4

Synthesis of 1,2-bis(di-tert-butylphosphinomethyl)-1′-3-bis(triphenylsilyl)ferrocene

(25) Part (I)

Preparation of 1-dimethylaminomethyl-2,1′-bis-triphenylsilyl ferrocene

(26) ##STR00041##

(27) To dimethylaminomethylferrocene (20 g, 82.26 mmol) in dry diethyl ether (300 ml) was added n-butyllithium (82.26 ml, 205.65 mmol, 2.5 eq) and TMEDA (13.66 ml, 90.49 mmol, 1.1 eq) and the reaction was stirred under N.sub.2 for 12 hours at room temperature. The solution was then cooled to −78° C. (dry ice/acetone bath) and quenched with chlorotriphenylsilane (50.94 g, 172.75 mmol, 2.1 eq) dissolved in dry THF (200 ml). The solution was then allowed to warm up to room temperature and further stirred for twelve hours resulting in a red solution.

(28) The reaction was then quenched with water, and stirred for a further fifteen minutes. The ethereal layer, containing product was separated and the aqueous layer was further extracted several times with diethyl ether. The combined ether fractions were dried over magnesium sulphate and filtered through celite. The ether solvent was removed by rotary evaporator (resulting in red oil). The product was purified by layering the oil with petrol and Et.sub.2O and leaving to crystallize overnight. The liquid residue was decanted and the orange/red crystals were dried under vacuum. A second crop of orange/red crystals were obtained with the layering of the decanted liquid and repeating the process: (42.75 g, 68% yield).

(29) Part (II)

Preparation of 1,2-bis-dimethylaminomethyl-3,1′-bis-triphenylsilyl ferrocene

(30) ##STR00042##

(31) To 1-dimethylaminomethyl-2,1′-bis-triphenylsilyl ferrocene (40 g, 52.63 mmol) in dry diethyl ether (400 ml) was added n-butyllithium (25.26 ml, 63.16 mmol, 1.2 eq) and the reaction was stirred under N.sub.2 for 20 hours at room temperature. Dry THF (250 ml) was then added and solution was then cooled to −78° C. (dry ice/acetone bath) and quenched with Eschenmoser's salt (12.65 g, 68.42 mmol, 1.3 eq). The solution was then allowed to warm up to room temperature and further stirred for twelve hours resulting in an orange solution.

(32) The reaction was then quenched with water, and stirred for a further fifteen minutes. The ethereal layer, containing product was separated and the aqueous layer was further extracted several times with diethyl ether. The combined ether fractions were dried over magnesium sulphate and filtered through celite.

(33) The ether solvent was removed by rotary evaporator (resulting in red oil). The product was purified by layering the oil with the minimum Et.sub.2O and a layer of petrol and leaving to crystallize overnight. The liquid residue was decanted and the red crystals were dried under vacuum. A second crop of red crystals were obtained with the layering of the decanted liquid and repeating the process: (21.50 g, 50% yield).

(34) Part (III)

(35) The 1,2-bis(dimethylaminomethyl)-1′-3-bis(triphenylsilyl)ferrocene (15.37 g, 18.84 mmol) and di-tert-butylphosphine (8.00 g, 54.79 mmol) were added together in a schlenk flask. To this was added acetic acid:acetic anhydride (100 ml: 10 ml) which had been degassed with nitrogen for 30 minutes. The resultant suspension was then heated to 130° C. for four hours. The solution was then cooled to room temperature and the solvent removed under vacuum. The residue was suspended in methanol (100 ml) and stirred for 20 minutes. The methanol was then removed under vacuum. The residue was then suspended in ethanol (50 ml) and the ethanol suspension heated to 80° C. The resultant suspension was then allowed to cool to room temperature and the ethanol soluble material filtered into a clean schlenk. The residue was dried under vacuum to give a pale orange solid. Yield=8.0 g, 42%. 95% pure. .sup.31P {.sup.1H} NMR (CDCl.sub.3, 161.9 MHz, 5); 23.9 (s), 20.4 (s) ppm

(36) Compound 5

Synthesis of 1,2-bis(di-tert-butylphosphinomethyl)-3-(triphenylsilyl)ferrocene

(37) Part (I)

Preparation of 1-dimethylaminomethyl-2-triphenylsilyl ferrocene

(38) ##STR00043##

(39) To dimethylaminomethylferrocene (20 g, 82.26 mmol) in dry diethyl ether (300 ml) was added n-butyllithium (41.13 ml, 102.82 mmol, 1.25 eq) and TMEDA (13.66 ml, 90.49 mmol, 1.1 eq) and the reaction was stirred under N.sub.2 for 12 hours at room temperature. The solution was then cooled to −78° C. (dry ice/acetone bath) and quenched with chlorotriphenylsilane (25.48 g, 86.38 mmol, 1.05 eq) dissolved in dry THF (200 ml). The solution was then allowed to warm up to room temperature and further stirred for twelve hours resulting in a red solution.

(40) The reaction was then quenched with water, and stirred for a further fifteen minutes. The ethereal layer, containing product was separated and the aqueous layer was further extracted several times with diethyl ether. The combined ether fractions were dried over magnesium sulphate and filtered through celite. The ether solvent was removed by rotary evaporator (resulting in red oil). The product was purified by layering the oil with petrol and Et.sub.2O and leaving to crystallize overnight. The liquid residue was decanted and the orange/red crystals were dried under vacuum. A second crop of orange/red crystals were obtained with the layering of the decanted liquid and repeating the process: (25.63 g, 62% yield).

(41) Part (II)

Preparation of 1,2-bis-dimethylaminomethyl-3,1′-bis-triphenylsilyl ferrocene

(42) To 1-dimethylaminomethyl-2-triphenylsilyl ferrocene (20 g, 39.87 mmol) in dry diethyl ether (400 ml) was added n-butyllithium (19.13 ml, 47.84 mmol, 1.2 eq) and the reaction was stirred under N.sub.2 for 20 hours at room temperature. Dry THF (250 ml) was then added and solution was then cooled to −78° C. (dry ice/acetone bath) and quenched with Eschenmoser's salt (9.59 g, 51.83 mmol, 1.3 eq). The solution was then allowed to warm up to room temperature and further stirred for twelve hours resulting in an orange solution.

(43) The reaction was then quenched with water, and stirred for a further fifteen minutes. The ethereal layer, containing product was separated and the aqueous layer was further extracted several times with diethyl ether. The combined ether fractions were dried over magnesium sulphate and filtered through celite. The ether solvent was removed by rotary evaporator (resulting in red oil). The product was purified by layering the oil with the minimum Et.sub.2O and a layer of petrol and leaving to crystallize overnight. The liquid residue was decanted and the red crystals were dried under vacuum. A second crop of red crystals were obtained with the layering of the decanted liquid and repeating the process: (14.7 g, 66% yield).

(44) Part (III)

(45) The diamine from Part (II) (5.00 g, 8.96 mmol) and di-tert-butylphosphine (3.50 g, 23.97 mmol) were added together in a schlenk flask. To this was added acetic acid:acetic anhydride (100 ml: 10 ml) which had been degassed with nitrogen for 30 minutes. The resultant suspension was then heated to 130° C. for three hours. The solution was then cooled to room temperature and the solvent removed under vacuum. The residue was suspended in methanol (50 ml) and stirred for 20 minutes. The methanol was then removed under vacuum. Pentane (50 ml) was then added and the pentane soluble material cannula transferred into a clean schlenk. The solvent was the removed under vacuum to give an orange/red oily solid. Yield=2.0 g, 30%. 90% pure. .sup.31P {.sup.1H} NMR (CDCl.sub.3, 161.9 MHz, 5); 26.0 (s), 20.3 (s) ppm

(46) Compound 6

Preparation of 1,2-bis(di-1-(3,5-dimethyladamantyl)phosphinomethyl)-1′-trimethylsilyl-ferrocene

(47) Part (I)

Preparation of 1-bromo-1′-trimethylsilyl ferrocene

(48) ##STR00044##

(49) To 1,1′-dibromoferrocene (10 g, 29.08 mmol) in dry THF (200 ml) cooled to −78° C. (dry ice/acetone bath) was added n-butyllithium (11.05 ml, 27.63 mmol, 0.95 eq) and the reaction was stirred under N.sub.2 for 30 min. Chlorotrimethylsilane (3.7 ml, 29.08 mmol, 1 eq) was then added dropwise and the solution was then allowed to warm up to room temperature and further stirred for twelve hours resulting in a red solution.

(50) The reaction was then quenched with water, and stirred for a further fifteen minutes. The ethereal layer, containing product was separated and the aqueous layer was further extracted several times with diethyl ether. The combined ether fractions were dried over magnesium sulphate and filtered through celite. The ether solvent was removed by rotary evaporator (resulting in red oil). The product was purified as the initial red band (petrol) by column chromatography. The resulting red oil was finally dried under vacuum: (7.11 g, 73% yield).

(51) Part (II)

Preparation of 1-dimethylaminomethyl-1′-trimethylsilyl ferrocene

(52) ##STR00045##

(53) To 1-bromo-1′-trimethylsilyl ferrocene (5.52 g, 16.37 mmol) in dry diethyl ether (100 ml) was added n-butyllithium (7.2 ml, 18.01 mmol, 1.1 eq) and the reaction was stirred under N.sub.2 for 1 hour at room temperature. Dry THF (100 ml) was then added and solution was then cooled to −78° C. (dry ice/acetone bath) and quenched with Eschenmoser's salt (3.33 g, 18 mmol, 1 eq). The solution was then allowed to warm up to room temperature and further stirred for twelve hours resulting in a yellow solution.

(54) The reaction was then quenched with water, and stirred for a further fifteen minutes. The ethereal layer, containing product was separated and the aqueous layer was further extracted several times with diethyl ether. The combined ether fractions were dried over magnesium sulphate and filtered through celite. The ether solvent was removed by rotary evaporator (resulting in red oil). The product was purified by column chromatography. Starting material was removed with petrol (10% Et.sub.2O) and the product was then obtained with 1:1 petrol/Et.sub.2O (5% triethylamine). The resulting red oil was finally dried under vacuum: (4.09 g, 79% yield).

(55) Part (III)

Preparation of 1,2-bis-dimethylaminomethyl-1′-trimethylsilyl ferrocene

(56) ##STR00046##

(57) To 1-dimethylaminomethyl-1′-trimethylsilyl ferrocene (3.86 g, 12.24 mmol) in dry diethyl ether (100 ml) was added n-butyllithium (5.88 ml, 14.69 mmol, 1.2 eq) and the reaction was stirred under N.sub.2 for 1 hour at room temperature. Dry THF (100 ml) was then added and solution was then cooled to −78° C. (dry ice/acetone bath) and quenched with Eschenmoser's salt (2.50 g, 13.47 mmol, 1.1 eq). The solution was then allowed to warm up to room temperature and further stirred for twelve hours resulting in an orange solution.

(58) The reaction was then quenched with water, and stirred for a further fifteen minutes. The ethereal layer, containing product was separated and the aqueous layer was further extracted several times with diethyl ether. The combined ether fractions were dried over magnesium sulphate and filtered through celite.

(59) The ether solvent was removed by rotary evaporator (resulting in red oil). The product was purified by column chromatography. Starting material was removed with petrol (10% Et.sub.2O) and the product was then obtained with 1:1 petrol/Et.sub.2O (5% triethylamine). The resulting red oil was finally dried under vacuum: (4.33 g, 95% yield).

(60) Part (IV)

Synthesis of 1,2-bis(di-1(3,5-dimethyladamantyl)phosphinomethyl)-1′(trimethylsilyl)ferrocene

(61) The diamine Part (III) (1.00 g, 2.68 mmol) was dissolved in acetic acid: acetic anhydride (18 ml: 2 ml) which had been degassed with nitrogen for 10 minutes. The diamine solution was then transferred by cannula into a 500 ml schlenk flask containing the dimethyl adamantyl phosphine (1.98 g, 5.36 mmol). The resultant suspension was then heated to 130° C. for five hours. The solution was then cooled to room temperature and the solvent removed under vacuum. The residue was suspended in methanol (50 ml) and stirred for 20 minutes. The methanol was then removed under vacuum. The residue was then washed with ethanol (50 ml) and the ethanol washings removed by cannula. The remaining solid was then dried under vacuum and isolated in the glovebox as a yellow/orange solid. Yield=1.10 g, 41%. 86% pure. .sup.31P {.sup.1H} NMR (CDCl.sub.3, 161.9 MHz, 5); 18.7 ppm.

(62) Compound 7

Preparation of 1,2-bis(di-tert-butyl(phosphinomethyl) 3,5,1′ tris-triphenylsilyl ferrocene

(63) Part (I)

Preparation of 1,2-bis-dimethylaminomethyl-3,5,1′tris-triphenylsilyl ferrocene

(64) ##STR00047##

(65) To 1,2-bis-dimethylaminomethyl-3,1′-bis-triphenylsilyl ferrocene (10.2 g, 12.48 mmol) (prepared as in compound 4 above) in dry diethyl ether (200 ml) was added n-butyllithium (5.99 ml, 14.98 mmol, 1.2 eq) and the reaction was stirred under N.sub.2 for 4 hours at room temperature. The solution was then cooled to −78° C. (dry ice/acetone bath) and quenched dropwise with chlorotriphenylsilane (4.78 g, 16.23 mmol, 1.3 eq) dissolved in the minimum amount of dry diethyl ether. The solution was then allowed to warm up to room temperature and further stirred for twelve hours resulting in a red solution.

(66) The reaction was then quenched with water, and stirred for a further fifteen minutes. The ethereal layer, containing product was separated and the aqueous layer was further extracted several times with diethyl ether. The combined ether fractions were dried over magnesium sulphate and filtered through celite. The ether solvent was removed by rotary evaporator (resulting in red oil). The product was purified by layering the oil with the minimum Et.sub.2O and a layer of petrol and leaving to crystallize overnight. The liquid residue was decanted and the red crystals obtained were dried under vacuum: (10.41 g, 78% yield).

(67) The produced 1,2-bis-dimethylaminomethyl-3,5,1′-tris-triphenylsilyl ferrocene (18.24 mmol) was made into the di-tert-butylphosphine as follows.

(68) Part (II)

Synthesis of 1,2-bis(di-tert-butylphosphinomethyl)-1′-3-5-tris(triphenylsilyl)ferrocene

(69) The diamine from Part (I) (10.41 g, 9.69 mmol) and di-tert-butylphosphine (5.00 g, 34.2 mmol) were added together in a schlenk flask. To this was added acetic acid:acetic anhydride (100 ml: 10 ml) which had been degassed with nitrogen for 30 minutes. The resultant suspension was then heated to 130° C. for four hours. The solution was then cooled to room temperature and the solvent removed under vacuum. The residue was suspended in methanol (100 ml) and stirred for 20 minutes. The methanol was then removed under vacuum. Pentane (50 ml) was then added and the pentane soluble material cannula transferred into a clean schlenk. The solvent was the removed under vacuum to give a pale orange/brown solid. Yield=1.7 g, 14%. 95% pure. .sup.31P {.sup.1H} NMR (CDCl.sub.3, 161.9 MHz, δ); 23.9 (s), 20.4 (s) ppm

(70) Compound 8

Preparation of 1,2-bis(di-tert-butylphosphinomethyl)-3,1′-bis-trimethylsilyl ferrocene

(71) Part (I)

Preparation of 1-dimethylaminomethyl-2,1′-bis-trimethylsilyl ferrocene

(72) ##STR00048##

(73) To dimethylaminomethylferrocene (30 g, 123.39 mmol) (Aldrich) in dry diethyl ether (200 ml) was added n-butyllithium (123.39 ml, 308.48 mmol, 2.5 eq) and TMEDA (20.48 ml, 135.73 mmol, 1.1 eq) and the reaction was stirred under N.sub.2 for 12 hours at room temperature. The solution was then cooled to −78° C. (dry ice/acetone bath) and quenched with chlorotrimethylsilane (34.45 ml, 271.46 mmol, 2.2 eq). The solution was then allowed to warm up to room temperature and further stirred for twelve hours resulting in an orange solution.

(74) The reaction was then quenched with water, and stirred for a further fifteen minutes. The ethereal layer, containing product was separated and the aqueous layer was further extracted several times with diethyl ether. The combined ether fractions were dried over magnesium sulphate and filtered through celite. The ether solvent was removed by rotary evaporator (resulting in red oil). The product was purified by column chromatography (large scale column). Small amounts of starting material were removed with petrol (5% triethylamine) and the product was then obtained with 1:1 petrol/Et.sub.2O (5% triethylamine). The resulting red oil was finally dried under vacuum: (40 g, 84% yield).

(75) Part (II)

Preparation of 1,2-bis-dimethylaminomethyl-3,1′-bis-trimethylsilyl ferrocene

(76) ##STR00049##

(77) To 1-dimethylaminomethyl-2,1′-bis-trimethylsilyl ferrocene (30 g, 77.42 mmol) in dry diethyl ether (200 ml) was added n-butyllithium (37.2 ml, 92.91 mmol, 1.2 eq) and the reaction was stirred under N.sub.2 for 20 hours at room temperature. Dry THF (250 ml) was then added and solution was then cooled to −78° C. (dry ice/acetone bath) and quenched with Eschenmoser's salt (17.18 g, 92.91 mmol, 1.2 eq). The solution was then allowed to warm up to room temperature and further stirred for twelve hours resulting in a red solution.

(78) The reaction was then quenched with water, and stirred for a further fifteen minutes. The ethereal layer, containing product was separated and the aqueous layer was further extracted several times with diethyl ether. The combined ether fractions were dried over magnesium sulphate and filtered through celite. The ether solvent was removed by rotary evaporator (resulting in red oil). The product was purified by column chromatography (large scale column). Small amounts of starting material were removed with petrol (5% triethylamine) and the product was then obtained with 1:1 petrol/Et.sub.2O (5% triethylamine). The resulting red oil was finally dried under vacuum: (32.11 g, 93% yield).

(79) Part (III)

(80) Compound 8 was prepared as compound 3 above using 1,2-bis-dimethylaminomethyl-3,1′-bis-trimethylsilyl ferrocene (9.23 mmol) instead of 1,2-bis(dimethylaminomethyl)-1′-(triphenylsilyl)ferrocene.

(81) Compound A

Synthesis of 1,2-bis(di-tert-butylphosphinomethyl)-4-CMe2Ph-benzene

(82) Part (I)

Synthesis of 4-CMe2Ph-o-xylene

(83) The 3,4-dimethylbenzophenone (15.0 g, 71.43 mmol) was added to a 500 ml schlenk flask, to this was added benzoic acid (150 mg). The solid was then dissolved in toluene (100 ml). To this was then added trimethyl aluminium (2.0M in toluene, 100 ml, 200 mmol). The resultant solution was then heated to 125° C. for hours. The solution was then allowed to cool to room temperature and was then quenched by the very slow addition of water (100 ml). This gave a white suspension, diethyl ether (150 ml) was then added and the suspension filtered. The filtrate was then dried over sodium sulphate and filtered. The filtrate was then dried under vacuum, this gave a colourless oil, yield=13.4 g, 84%.

(84) The 4-CMe.sub.2Ph-o-xylene ((13.0 g, 58.0 mmol) from Part I above and NaOBu.sup.t (16.7 g, 174.1 mmol) were added together in a schlenk flask. To this was then added heptane (150 ml) and TMEDA (26.1 ml, 174.1 mmol), Bu.sup.nLi (2.5M in hexanes, 69.6 ml, 174.1 mmol) was then added slowly. The addition of the butyl lithium gave an immediate colour change from colourless to yellow to orange to dark red. The resultant solution was then heated to 70° C. for three hours. This gave a dark red suspension. The suspension was cooled to room temperature and the supernatant liquid removed by cannula the brown precipitate residue was then washed with pentane (200 ml). The pentane washings were then removed by cannula. The solid residue was then suspended in pentane (250 ml) and then cooled to 0° C. Bu.sup.t.sub.2PCl (19.8 ml, 104.5 mmol) was then added dropwise to the suspension. The resultant suspension was then stirred for overnight. Water (100 ml) was degassed with nitrogen gas for 30 minutes and then added to the suspension. This gave a biphasic solution. The upper (organic phase) was diluted with pentane (100 ml) and the organic phase removed by cannula into a clean schlenk flask. The aqueous layer was then washed with a further 100 ml of pentane and the pentane extracts combined. The pentane extracts were then dried over sodium sulphate and transferred into a clean schlenk flask by cannula. The solvent was then removed under vacuum to give a red/brown oil. Methanol (100 ml) was then added and the resultant suspension heated to reflux, the suspension formed was then allowed to cool to room temperature and the methanol soluble material removed by cannula. The residue was dried under vacuum to give an orange/brown oil. Yield=10.9 g, 45%. .sup.31P {.sup.1H} NMR was consistent with the structure, the compound was cleaned up by conversion to the bis methane sulphonate salt—see below.

Synthesis of bis methane sulphonic acid salt of 1,2-bis(di-tert-butylphosphinomethyl)-4-CMe2Ph-benzene

(85) The phosphine (Compound A) (10.9 g, 21.3 mmol) was suspended in methanol (100 ml). To this was added methane sulphonic acid (2.76 ml, 42.6 mmol). The resultant solution was then stirred for one hour. The methanol was then removed under vacuum to give viscous brown oil. Diethyl ether (50 ml) was then added, and the ether soluble material was removed by cannula. The remaining material was then dried under vacuum this gave a sticky yellow solid. Diethyl ether (60 ml) was then added and the solid was stirred in the ether with a spatula. The ether soluble material was then removed and the residue dried under vacuum, this gave a free flowing pale yellow solid. Yield=11.0 g, 85%. 95% pure. .sup.31P {.sup.1H} NMR (CDCl.sub.3, 161.9 MHz, δ); 42.6 (br), 39.0 (br) ppm.

(86) Compound B

Synthesis of 1,2-bis(di-tert-butylphosphinomethyl)-4-tert-butyldimethylsilyl benzene

(87) Part (I)

Synthesis of 4-tert-butyldimethylsilyl-o-xylene

(88) Magnesium ribbon (2.91 g, 115.41 mmol) was added to a schlenk flask. To this was added a few (3-4) crystals of iodine. THF (150 ml) was then added to give an orange/yellow solution. 4-bromo-o-xylene (19.41 g, 104.91 mmol) was diluted with THF (80 ml) and then added slowly over one hour to the magnesium suspension, the reaction flask being placed in a warm (50° C.) water bath for the duration of the reaction. This gave a dark orange/brown solution with some insoluble magnesium. This solution was then heated to 85° C. for one hour. The solution was then allowed to cool to room temperature before being cannula transferred into a clean schlenk away for the unreacted magnesium. The THF solution was then cooled to −78° C. before a solution of tert-butyldimethylsilyl chloride (15.81 g, 104.91 mmol) in THF (50 ml) was added. The resultant solution was then allowed to stir at −78° C. for thirty minutes before being allowed to warm to room temperature. The resultant solution was then stirred at room temperature overnight. The solution was quenched by the addition of water (100 ml). Ether (100 ml) was then added and the biphasic mixture separated. The aqueous layer was washed with ether (100 ml) and the organic extracts combined. The organic extracts were then dried over sodium sulphate before being filtered. The filtrate was then dried under vacuum to give a white solid. Yield=15.64 g, 68%.

(89) Part (II)

(90) The 4-tert-butyldimethylsilyl-o-xylene (7.5 g, 34.1 mmol) from Part (I) above and NaOBu.sup.t (13.1 g, 136.4 mmol) were added together in a schlenk flask. Heptane (100 ml) was then added followed by TMEDA (20.5 ml, 136.4 mmol), Bu.sup.nLi (2.5M in hexanes, 54.5 ml, 136.4 mmol) was then added slowly. The butyl lithium addition gave an immediate colour change from colourless to yellow to orange to dark red. The solution was then heated to 75° C. for three hours. This gave a brown solution with a small amount of precipitate. The solution was then cooled to 0° C. and Bu.sup.t.sub.2PCl (11 .ml, 62.5 mmol) was then added dropwise to the suspension. The resultant suspension was then stirred overnight. Water (100 ml) was degassed with nitrogen gas for 30 minutes and then added to the suspension. This gave a biphasic solution. The upper (organic phase) was diluted with pentane (150 ml) and the organic phase removed by cannula into a clean schlenk flask. Pentane (150 ml) was added to the aqueous residues and the pentane extracts combined. The pentane extracts were then dried over sodium sulphate and transferred into a clean schlenk flask by cannula. The solvent was then removed under vacuum to give a brown oil. To this was added methanol (50 ml) which give a biphasic solution. This was then heated to reflux (70° C.) before being allowed to cool to room temperature. The methanol soluble material was then cannula transferred into a clean schlenk flask and then placed in the freezer at −20° C. overnight. This gave the formation of a brown oil. The methanol mother liquor was then transferred into a clean schlenk flask and placed in the freezer. Upon standing in the freezer for three days a pale brown solid had formed. The methanol mother liquor was removed and the residue dried under vacuum. This gave a pale brown solid. Yield=0.80 g, 5%. 95% pure. .sup.31P {.sup.1H} NMR (CDCl.sub.3, 161.9 MHz, 5); 28.3 (s), 26.0 (s) ppm.

(91) The comparative examples were obtained as follows: —

(92) Comparative 1

(93) 1,2-bis(di-tert-butylphosphinomethyl)benzene is available from Aldrich.

(94) Comparative 2

Synthesis of 1,2-bis(di-tert-butylphosphinomethyl)ferrocene

(95) Part (I)

Preparation of 1,2-bis-(dimethylaminomethyl)ferrocene

(96) n-Butyllithium (Aldrich, 2.5 molar in hexane, 24 ml, 54 mmol) is added to a solution of (dimethylaminomethyl)ferrocene (Aldrich, 13.13 g, 10.69 ml, 48.97 mmol) in diethyl ether (80 ml) under nitrogen at a temperature of 25° C. and the reaction mixture stirred for 4 hours. The resulting red solution is then cooled to approximately −70° C. in a dry ice/acetone bath and Eschenmosers salt (ICH.sub.2NMe.sub.2) (Aldrich, 10 g, 54 mmol) is added. The reaction is allowed to warm to room temperature and stirred overnight.

(97) The resultant solution is quenched with excess aqueous sodium hydroxide and the resulting product extracted with diethyl ether (3×80 ml) dried over anhydrous magnesium sulfate, filtered over celite, and volatiles removed in vacuo to yield the crude title compound as a light orange crystalline solid. The crude product is recrystallised from light petrol with cooling to −17° C. and the recrystallised product washed with cold petrol to yield the title compound as a light orange solid (13.2 g, 74%). The compound can be further purified by sublimation to give 8.5 g (52%) of the Part (I) title compound (mpt 74° C.)

(98) .sup.1H NMR (250 MHz; CDCl.sub.3): δ4.23 (brd, 2H); 4.11-4.10 (t, 1H); 4.04 (s, 5H); 3.43, 3.38, 3.23, 3.18 (AB quartet, 2H); 2.22 (s, 6H).

(99) .sup.13C NMR (63 MHz; CDCl.sub.3): δ83.81; 70.40; 69.25; 66.84; 57.35; 45.23.

(100) Elemental analysis: Found: C, 63.7%; H, 8.9%; N, 9.5%

(101) Calculated: C, 64.0%; H, 8.1%; N, 9.4%

(102) Part (II)

(103) Into a 500 ml schlenk flask was added the di-tert-butyl phosphine (13.3 g, 90.8 mmol) and the 1,2-bis(dimethylaminomethyl)ferrocene (13.6 g, 45.4 mmol). This was then suspended in a mixture of acetic acid:acetic anhydride 100 ml: 30 ml) which had been degassed with nitrogen for 30 minutes. The suspension was then heated to 130° C. and kept at this temperature for two hours. The resultant solution was then allowed to cool to ambient temperature and the solvent removed under vacuum. The resultant sticky solid was suspended in methanol (50 ml) and stirred for 30 minutes. The methanol was then removed under vacuum and the residue suspended in ethanol (50 ml). The ethanol suspension was then heated up to 70° C. The resultant solution stirred was allowed to cool to room temperature before being placed in the freezer at −20° C. overnight. This gave a large amount of an orange crystalline product. The ethanol mother liquor was removed by cannula and the solid dried under vacuum. This gave free following orange crystals. Yield 15.1 g, 57%. .sup.31P NMR{.sup.1H} (CDCl.sub.3, 161.9 MHz, δ); 23.6 ppm, 99% pure.

(104) Comparative 3

Synthesis of 1,2-bis(di-1-(3,5-dimethyladamantyl)phosphinomethyl)ferrocene

(105) Part (I)

Preparation of 1-hydroxymethyl-2-dimethylaminomethyl ferrocene

(106) n-Butyl lithium (Aldrich, 1.6 molar in diethyl ether, 5.14 ml, 8.24 mmol) is added to a solution of 1-dimethylaminomethyl ferrocene (Aldrich, 1.0 g, 4.12 mmol) in diethyl ether (20 mL) under argon. The reaction is stirred for 3 hours and develops a reddish colour. The solution is then cooled in a dry ice/acetone bath, calcined para-formaldehyde (0.247 g, 2 times excess) added and the resultant mixture stirred overnight at room temperature. The reaction is then quenched with water, extracted with diethyl ether, dried over MgSO.sub.4, and filtered over celite. The solvent is removed in vacuo to yield crude title compound. The crude product is applied to a neutral alumina column, which is eluted with petrol/diethyl ether (9:1 ratio) to remove the starting material, 1-dimethylaminomethyl ferrocene. The column is then eluted with substantially pure ethyl acetate to elute the title compound. The ethyl acetate is removed in vacuo, to yield the title compound as an orange oil/crystalline mass.

(107) .sup.1H NMR (250 MHz; CDCl.sub.3) δ2.131 (s, 6H), δ2.735 (d, 1H, 12.512 Hz), δ3.853 (d, 1H, 12.512 Hz), δ3.984 (dd, 1H, 2.156 Hz), δ4.035 (s, 5H), δ4.060 (dd, 1H, 2.136 Hz) δ4.071 (d, 1H, 12.207 Hz), δ4.154 (m, 1H), δ4.73 (d, 1H, 12.207 Hz).

(108) .sup.13C NMR (61 MHz; CDCl.sub.3) δ7.688, δ84.519, δ70.615, δ68.871, δ68.447, δ65.369, δ60.077, δ58.318, δ44.414

(109) COSY 2D .sup.1H NMR

(110) Partly obscured doublet at 4.071 ppm and its coupling to the doublet at 4.73 ppm confirmed.

(111) Infrared spectra (CHCl.sub.3) (c.a. 0.06 g/0.8 mL) 2953.8 cm.sup.−1, 2860.6 cm.sup.−1, 2826.0 cm.sup.−1, 2783.4 cm.sup.−1, 1104.9 cm.sup.−1

(112) Part (II)

(113) Into a 500 ml schlenk flask was added the dimethyladamantyl phosphine (29.5 g, 82.3 mmol) and the 1-hydroxymethyl-2-dimethylaminomethyl ferrocene (11.2 g, 41.2 mmol) in the glovebox. This was then suspended in a mixture of acetic acid:acetic anhydride (150 ml: 30 ml) which had been degassed with nitrogen for 30 minutes. The suspension was then heated to 130° C. and kept at this temperature for 60 minutes. The resultant solution was then allowed to cool to ambient temperature and the solvent removed under vacuum. The resultant sticky solid was suspended in methanol (50 ml) and stirred for 30 minutes. The methanol was then removed under vacuum and the residue suspended with ethanol (100 ml). The ethanol suspension was then stirred until a yellow/orange powder was formed and a dark red/brown solution. The ethanol soluble material washings were then removed by filtration and the residue dried under vacuum. This gave a free flowing yellow/orange solid which was isolated in the glovebox. Yield 26.7 g, 70.1%. .sup.31P NMR {.sup.1H} (CDCl.sub.3, 161.9 MHz, δ); 18.9 ppm, 95% pure.

(114) Test Results

(115) Table 1 shows the activity of six phosphine ligands in catalysis after they have first been heated at 80° C. overnight in the presence of CO/Ethene. In each case the number of moles of palladium, ligand and acid are the same as a standard batch run where the ligands have not been pre-treated (Table 2). Hence the gas uptake and weight gain of a treated (premature aged) ligand can be compared to a standard for the untreated ligand. Thermal treatment is used to investigate differences in catalyst stability which would not be evident in a standard 3 hour batch test. In other words, conditions are employed which would result in premature ageing of the catalyst.

(116) It can be seen that the phosphine containing a trimethylsilyl group at the 4 position of the benzene ring retains most of its activity under these ageing conditions whereas the unsubstituted ligand 1,2-bis(di-tert-butylphosphinomethyl) benzene has lost 85% of its activity of an untreated standard. In all the cases where a substituent on the ring is present an improvement over 1,2-bis(di-tert-butylphosphinomethyl)benzene is observed.

(117) TABLE-US-00001 TABLE 1 Results for New Ligands and 1,2-Bis (di- tert-butylphosphinomethyl)benzene for comparison Average % Activity Average Max of Gas Uptake TON MeP of Standard from 2.251 recycle (based on Reservoir (mol Pd/mol GAS UPTAKE Ligand (bar) MeP) TON) 0 20.6 88182 100.34 12.5 52480 56.00 4.4 12095 13.01 20.3 82359 78.3 21.5 86493 98.86 21.3 86239 98.3

(118) TABLE-US-00002 TABLE 2 Standards used for all aged ligands Average Max Gas Uptake TON MeP of from 2.251 recycle Reservoir (mol Pd/mol Ligand (bar) MeP) 23.2 87886 22.4 93792 22.9 92730 26.0 105206 0 22.0 87487 21.7 87735
Experimental Test Method
Part 1 Ageing

(119) Catalyst solutions were prepared using standard schlenk line techniques. 1.45×10.sup.−5 moles Pd.sub.2(dba).sub.3 and 6 equivalents of the phosphine ligand were weighed out into a 500 ml round bottom flask using a nitrogen purge glovebox. The flask was then transferred to a schlenk line. To this flask was added 172 ml (63.2 wt %) degassed MeP and 116 ml (36.8 wt %) degassed MeOH. To this was added 450 equivalents (420 μl) methane sulphonic acid.

(120) The pre-evacuated autoclave was then charged with the reaction solution. At ambient temperature, 5 bar ethene was added followed by 10 bar 50:50 ethene/CO mixture giving a total of 15 bar gas pressure. The stirrer was then started (1000 rpm) and the autoclave heated to 80° C. Once at this temperature the time was noted and the autoclave was left stirring under these conditions overnight for 17 hours.

(121) The initial solvent composition of 63.2 wt % MeP and 36.8 wt % MeOH was used so that the consumption of 10 bar ethene/CO would result in the production of MeP to yield a new and optimum composition of 70 wt % MeP, 30 wt % MeOH ready for the second part of the experiment.

(122) Part 2 Testing

(123) After this time had elapsed, the autoclave total pressure had dropped to around 5 bar, as the 10 bar of 1:1 ethene/CO had fully reacted. The autoclave was then heated from 80° C. to 100° C. At this temperature ethene was immediately added to bring the pressure up to 10.2 bar (approx 8 bar of ethylene above solvent vapour pressure at 100° C.). It was assumed that all the CO initially present had reacted by this stage meaning only ethene remained in the autoclave. The reaction was immediately initiated by opening the autoclave to a 40 bar 50:50 ethene/CO supply resevoir in a 2.251 cylinder via a pressure regulating valve (Tescom 1500 model no. 26-1025-24-007) supplied by Tescom Corporation set to allow a pressure in the autoclave of 12.2 bar, allowing for a 9:1 ethene/CO ratio to be achieved in the gas phase. This reaction was allowed to proceed for 3 hours, after which the autoclave was cooled and vented.

(124) Part 3 Standard TON Determination

(125) To calculate the average % activity compared with the standard, reaction standard solutions were prepared in the same way, using standard Schlenk line techniques. In a nitrogen purge glove box, 7.8 mg of Pd.sub.2 dba.sub.3 (1.45*10.sup.−5 moles) and 6 equivalents of phosphine ligand (8.7*10.sup.−5 moles), where weighed into a 500 ml round bottom flask. The flask was then transferred to a Schlenk line. The ligand and palladium were then dissolved in 125 ml of degassed methyl propionate. In order to aid complexation, the palladium and ligand were dissolved initially in methyl propionate and stirred for a period of 45 minutes, before addition of further solvents to the solution. This allows for the in situ formation of a neutral, trigonal planar Pd (0) complex [Pd(ligand)(dba)].

(126) After complexation, 175 ml of methyl propionate/methanol mixture (50% by weight methanol, 50% by weight methyl propionate) was degassed and added to the flask. Addition of methane sulfonic acid (MSA), 420 μl, completes the preparation of the catalyst solution. The final composition of the solution is approximately 70 w't % methylpropionate, 30 wt % methanol.

(127) The catalytic solution was added to the pre-evacuated autoclave and heated to 100 C. The autoclave was then pressured with 8 bars of ethene above vapour pressure giving a total pressure of 10.2 bars at 100 C. Next the autoclave was pressured to 12.2 bars with addition of CO:ethene (1:1 gas) charged from the 10 liter reservoir. A regulatory valve ensures that the pressure of the autoclave is maintained throughout the reaction at 12.2 bars through constant injection of gas from the 10 liter reservoir. The pressure of the reservoir as well as the reactor temperature was logged throughout the reaction period of 1 hr.

(128) The moles produced at any point in either reaction are calculated from the drop in reservoir pressure by assuming ideal gas behaviour and 100% selectivity for methyl propionate, which allowed reaction TON and rate to be obtained. The results are shown in Tables 1 and 2.

Recycling Examples

(129) Experimental

(130) Using standard Schlenk line techniques, reaction solutions were prepared by dissolving 1.45×10.sup.−5 moles of Pd and 8.7×10.sup.−5 moles of ligand in 300 ml of solvent consisting of, 70% by weight methyl propionate and 30% by weight methanol. The palladium and ligand were allowed to complex in methyl propionate, before the methanol was added to the mixture. Addition of 420 μl of methane sulfonic acid (450 equivalents) completed the preparation of the catalyst solution.

(131) The catalytic solution was added to the pre-evacuated autoclave and heated to 100° C. The autoclave was then pressured with 8 bars of ethene above vapour pressure giving a total pressure of 10.2 bars at 100° C. Next the autoclave was pressured to 12.2 bars with addition of CO:ethene (1:1 gas) charged from a 10 liter reservoir at higher pressure. A regulatory valve ensures that the pressure of the autoclave is maintained throughout the reaction at 12.2 bars through constant injection of gas from the 10 liter reservoir. The pressure of the reservoir as well as the reactor temperature was logged throughout the reaction period of 3 hrs. The moles produced at any point in the reaction can be calculated from the drop in reservoir pressure by assuming ideal gas behaviour and 100% selectivity for methyl propionate, allowing reaction TON with the particular ligand to be obtained.

(132) After the reaction period, the autoclave was cooled and vented. The reaction solution was collected from the base of the vessel and immediately placed under an inert atmosphere. The solution was then reduced under pressure, to approximately 50 mls. Concentrating the solution removes the methanol (the most volatile component of the mixture) and any traces of CO, both of which can reduce Pd (II) to Pd (0) causing the palladium to precipitate out of solution as metallic palladium. This concentrated solution, was left to stand overnight under an inert atmosphere and was then used to form the basis of the next reaction solution with addition of 200 ml of methyl propionate, 100 ml of methanol and 140 μl of methane sulfonic acid (150 equivalents). Excess acid was added to offset a possible loss in acid upon concentrating of the solution. This recycled material was then added to the autoclave and reacted under the same set of conditions as before. The catalyst was recycled in this way, until a significant drop in reaction TON was observed. Catalyst recycle was discontinued when the TON dropped below 20000 moles MeP/Mole Pd in a single run.

(133) Recycling Experimental Data

(134) The turnover number (TON) expressed in moles of MeP produced per mole of palladium for each recycle experiment is detailed in Table 3. It can be seen that the substituted ferrocene based ligands exhibit enhanced stability over the unsubstituted equivalent.

(135) TABLE-US-00003 TABLE 3 TON (moles MeP/Mole Recycle Number Pd) Cumulative TON Initial Run 90834 90834 Recycle 1 79113 169947 Recycle 2 84796 254743 Recycle 3 80001 334744 Recycle 4 71211 405955 Recycle 5 17936 423891 Initial run 84772 84772 Recycle 1 71637 156409 Recycle 2 69118 225527 Recycle 3 42847 268374 Recycle 4 14227 282601 Initial Run 90000 90000 Recycle 1 91968 181968 Recycle 2 80355 262323 Recycle 3 72307 334630 Recycle 4 57821 392451 Recycle 5 86050 478501 Recycle 6 32934 511436 Recycle 7 9534 520969
Std Batch Experiments in 70 wt % MeP, 30 wt % MeOH of Highly Substituted Ligands
Experimental

(136) Reaction solutions were prepared, using standard Schlenk line techniques. In a nitrogen purge glove box, 7.8 mg of Pd.sub.2 dba.sub.3 (1.45×10.sup.−5 moles) and 6 equivalents of phosphine ligand (8.7×10.sup.−5 moles), where weighed into a 500 ml round bottom flask. The flask was then transferred to a Schlenk line. The ligand and palladium was then dissolved in 125 ml of degassed methyl propionate. In order to aid complexation, the palladium and ligand were dissolved initially in methyl propionate and stirred for a period of minutes, before addition of further solvents to the solution. This allows for the in situ formation of a neutral, trigonal planar Pd (0) complex [Pd(ligand)(dba)].

(137) After complexation, 175 ml of methyl propionate/methanol mixture (50% by weight methanol, 50% by weight methyl propionate) was degassed and added to the flask. Addition of methane sulfonic acid (MSA), 420 μl, completes the preparation of the catalyst solution.

(138) The catalytic solution was added to the pre-evacuated autoclave and heated to 100° C. The autoclave was then pressured with 8 bars of ethene above vapour pressure giving a total pressure of 10.2 bars at 100° C. Next the autoclave was pressured to 12.2 bars with addition of CO:ethene (1:1 gas) charged from the 10 liter reservoir. A regulatory valve ensures that the pressure of the autoclave is maintained throughout the reaction at 12.2 bars through constant injection of gas from the 10 liter reservoir. The pressure of the reservoir as well as the reactor temperature was logged throughout the reaction period of 1 hrs. The moles produced at any point in the reaction can be calculated from the drop in reservoir pressure by assuming ideal gas behaviour and 100% selectivity for methyl propionate, allowing reaction TON to be obtained.

(139) TABLE-US-00004 TABLE 4 Rate after 1 TON after 1 Maximum Initial rate hour hour 39787 39543 35068 67117 57599 59995 54449 53081 48798 61472 56391 57137 43823 36346 38317 0 51875 45793 51052 55565 44176 47783

(140) From the above data it can be seen that substitution of the cyclopentadienyl ring at positions on both the top and bottom rings provides more active and stable catalysts. In addition, bulkier ligands and multiply substituted species provide further improvements in stability.

(141) The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

(142) All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

(143) Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

(144) The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.