Group 5 metal complexes for catalytic amine functionalization

Abstract

This application pertains to group 5 metal complexes having the structure of Formula I: ##STR00001##
and their potential utility in catalyzing α-alkylation of secondary amine-containing moieties.

Claims

1. A metal complex having the structure of Formula I: ##STR00196## wherein: (i) R.sup.1 and R.sup.2 are each independently H; a C.sub.1-C.sub.40 substituted or unsubstituted linear, branched or cyclic alkyl, alkenyl or alkynyl; a substituted or unsubstituted aryl; or a substituted or unsubstituted heterocyclic group; or R.sup.1 and R.sup.2 are bonded together thereby forming, together with the nitrogen atom they are both bound to, a heterocycle; and R.sup.3 is H; a C.sub.1-C.sub.40 substituted or unsubstituted linear, branched or cyclic alkyl, alkenyl or alkynyl; a substituted or unsubstituted aryl; or a substituted or unsubstituted heterocyclic group; or (ii) R.sup.1 is H; a C.sub.1-C.sub.40 substituted or unsubstituted linear, branched or cyclic alkyl, alkenyl or alkynyl; a substituted or unsubstituted aryl; or a substituted or unsubstituted heterocyclic group; and R.sup.3 is bonded together with R.sup.2 to form a heterocycle; M is a group 5 metal; a=1or 2 and b=2 or 3, wherein the sum of a and b is 4; each X is a halogen substituent; and each R.sup.4 is independently H; or a C.sub.1-C.sub.20 substituted or unsubstituted, linear, branched or cyclic alkyl, optionally comprising heteroatoms.

2. The metal complex of claim 1, wherein each X is independently Cl or Br, a=1 and b=3.

3. The metal complex of claim 1, wherein R.sup.1 and R.sup.2 are bonded together to form, together with the nitrogen atom they are both bound to, a 6-membered ring, which optionally may be substituted.

4. The metal complex of claim 1, wherein: R.sup.1 and R.sup.2 are each phenyl; R.sup.1 is phenyl and R.sup.2 is isopropyl; R.sup.1 and R.sup.2 are bonded together to form, together with the nitrogen atom they are both bound to, piperidinyl; R.sup.1 is phenyl and R.sup.2 is methyl; R.sup.1 is methyl and R.sup.2 is 1-phenylethyl; R.sup.1 is methyl and R.sup.2 is isopropyl; or R.sup.1 is methyl and R.sup.2 is diphenylmethyl.

5. The metal complex of claim 1, wherein R.sup.3 is: phenyl; 2,6-dimethyl phenyl; 2,6-di(isopropyl) phenyl; or ##STR00197##

6. The metal complex of claim 1, wherein R.sup.3 is bonded together with R.sup.2 to form, together with each of the nitrogen atoms they are bound to, a 5-membered ring, which optionally may be substituted.

7. The metal complex of claim 6, having the structure: ##STR00198## wherein R.sup.1 is methyl, tert-butyl, phenyl, cyclohexyl or adamantyl.

8. The metal complex of claim 1, wherein R.sup.4 is —CH.sub.2Si(CH.sub.3).sub.3.

9. The metal complex of claim 1, wherein M is tantalum (Ta).

10. The metal complex of claim 1, which metal complex is: ##STR00199##

11. A method of synthesizing a metal complex of Formula I, the method comprising reacting a group 5 metal salt of Formula VII with one equivalent of an amide of Formula VIII according to the following reaction: ##STR00200## wherein: (i) R.sup.1 and R.sup.2 are each independently H; a C.sub.1-C.sub.40 substituted or unsubstituted linear, branched or cyclic alkyl, alkenyl or alkynyl; a substituted or unsubstituted aryl; or a substituted or unsubstituted heterocyclic group; or R.sup.1 and R.sup.2 are bonded together thereby forming, together with the nitrogen atom they are both bound to, a heterocycle; and R.sup.3 is H; a C.sub.1-C.sub.40 substituted or unsubstituted linear, branched or cyclic alkyl, alkenyl or alkynyl; a substituted or unsubstituted aryl; or a substituted or unsubstituted heterocyclic group; or (ii) R.sup.1 is H; a C.sub.1-C.sub.40 substituted or unsubstituted linear, branched or cyclic alkyl, alkenyl or alkynyl; a substituted or unsubstituted aryl; or a substituted or unsubstituted heterocyclic group; and R.sup.3 is bonded together with R.sup.2 to form a heterocycle; M is a group 5 metal; a=1 or 2 and b=2 or 3, wherein the sum of a and b is 4; c=2 or 3 and d=2 or 3, wherein the sum of c and d is 5; each X is a halogen substituent; and each R.sup.4 is independently H; or a C.sub.1-C.sub.20 substituted or unsubstituted, linear, branched or cyclic alkyl, optionally comprising heteroatoms.

12. A method for α-alkylation of a secondary amine-containing moiety, the method comprising: (i) reacting said secondary amine-containing moiety with an olefin in the presence of a metal complex as defined in claim 1.

13. The method of claim 12, further comprising: (ii) isolating a product formed in step (i).

14. The method of claim 12, wherein the secondary amine-containing moiety is a C.sub.4-C.sub.100 linear, branched, or cyclic alkyl, optionally substituted and/or comprising heteroatoms.

15. The method of claim 12, wherein the secondary amine-containing moiety is substituted with a halogen, an ether, another amine, an alkyl, an alkene, an acetal, a phosphine, an amide, an alkyne, an imine, a nitrile, an isocyanide, an epoxide, a boronic acid ester, a phenyl that optionally may be substituted and/or part of a condensed ring system, or any combination thereof.

16. The method of claim 12, wherein the olefin is: ##STR00201##

17. The method of claim 12, wherein the secondary amine-containing moiety is: pyrrolidine; ##STR00202## wherein Z is H, OCF.sub.3, F, Cl, Br, I, or OCH.sub.3.

18. The method of claim 12, wherein the reaction conditions comprise a reaction temperature in the range from 90° C. to 150° C.

19. The method of claim 12, wherein the reaction conditions comprise a solvent, wherein the solvent is toluene, benzene, or a mixture thereof.

20. The method of claim 12, wherein the metal complex is generated in situ from a group 5 metal salt of Formula VII
MX.sub.c(R.sup.4).sub.d  (Formula VII) wherein: M is a group 5 metal; c=2 or 3 and d=2 or 3, wherein the sum of c and d is 5; and each R.sup.4 is independently H; or a C.sub.1-C.sub.20 substituted or unsubstituted, linear, branched or cyclic alkyl, optionally comprising heteroatoms, in combination with an amide of Formula VIII ##STR00203## wherein: (i) R.sup.1 and R.sup.2 are each independently H; a C.sub.1-C.sub.40 substituted or unsubstituted linear, branched or cyclic alkyl, alkenyl or alkynyl; a substituted or unsubstituted aryl; or a substituted or unsubstituted heterocyclic group; or R.sup.1 and R.sup.2 are bonded together thereby forming, together with the nitrogen atom they are both bound to, a heterocycle; and R.sup.3 is H; a C.sub.1-C.sub.40 substituted or unsubstituted linear, branched or cyclic alkyl, alkenyl or alkynyl; a substituted or unsubstituted aryl; or a substituted or unsubstituted heterocyclic group; or (ii) R.sup.1 is H; a C.sub.1-C.sub.40 substituted or unsubstituted linear, branched or cyclic alkyl, alkenyl or alkynyl; a substituted or unsubstituted aryl; or a substituted or unsubstituted heterocyclic group; and R.sup.3 is bonded together with R.sup.2 to form a heterocycle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In drawings which illustrate embodiments of the invention,

(2) FIG. 1 is a .sup.1H NMR spectrum (300 MHz, CDCl.sub.3, 298 K) of 3-(2,6-dimethylphenyl)-1,1-diphenylurea.

(3) FIG. 2 is a .sup.13C NMR spectrum (75 MHz, CDCl.sub.3, 298 K) of 3-(2,6-dimethylphenyl)-1,1-diphenylurea.

(4) FIG. 3 is a .sup.1H NMR spectrum (300 MHz, CDCl.sub.3, 298 K) of 3-(2,6-dimethylphenyl)-1-isopropyl-1-phenylurea.

(5) FIG. 4 is a .sup.13C NMR spectrum (75 MHz, CDCl.sub.3, 298 K) of 3-(2,6-dimethylphenyl)-1-isopropyl-1-phenylurea.

(6) FIG. 5 is a .sup.1H NMR spectrum (300 MHz, CDCl.sub.3, 298 K) of 4-bromo-N-(2-methyloctyl)aniline.

(7) FIG. 6 is a .sup.13C NMR spectrum (100 MHz, CDCl.sub.3, 298 K) of 4-bromo-N-(2-methyloctyl)aniline.

(8) FIG. 7 is a .sup.1H NMR spectrum (300 MHz, CDCl.sub.3, 298 K) of 4-bromo-N-(cyclooctylmethyl)aniline.

(9) FIG. 8 is a .sup.13C NMR spectrum (100 MHz, CDCl.sub.3, 298 K) of 4-bromo-N-(cyclooctylmethyl)aniline.

(10) FIG. 9 is a .sup.1H NMR spectrum (300 MHz, CDCl.sub.3, 298 K) of 4-chloro-N-(cyclooctylmethyl)aniline.

(11) FIG. 10 is a .sup.13C NMR spectrum (100 MHz, CDCl.sub.3, 298 K) of 4-chloro-N-(cyclooctylmethyl)aniline.

(12) FIG. 11 is a .sup.1H NMR spectrum (300 MHz, CDCl.sub.3, 298 K) of N-(cyclooctylmethyl)-4-fluoroaniline.

(13) FIG. 12 is a .sup.13C NMR spectrum (75 MHz, CDCl.sub.3, 298 K) of N-(cyclooctylmethyl)-4-fluoroaniline.

(14) FIG. 13 is a .sup.1H NMR spectrum (300 MHz, CDCl.sub.3, 298 K) of N-(2-methyloctyl)-4-(trifluoromethoxy)aniline.

(15) FIG. 14 is a .sup.13C NMR spectrum (75 MHz, CDCl.sub.3, 298 K) of N-(2-methyloctyl)-4-(trifluoromethoxy)aniline.

(16) FIG. 15 is a .sup.1H NMR spectrum (300 MHz, CDCl.sub.3, 298 K) of N-(cyclooctylmethyl)-4-(trifluoromethoxy)aniline.

(17) FIG. 16 is a .sup.13C NMR spectrum (75 MHz, CDCl.sub.3, 298 K) of N-(cyclooctylmethyl)-4-(trifluoromethoxy)aniline.

(18) FIG. 17 is a .sup.1H NMR spectrum (300 MHz, CDCl.sub.3, 298 K) of N-(2-methyloctyl)benzo[d][1,3]dioxol-5-amine.

(19) FIG. 18 is a .sup.13C NMR spectrum (75 MHz, CDCl.sub.3, 298 K) of N-(2-methyloctyl)benzo[d][1,3]dioxol-5-amine.

(20) FIG. 19 is a .sup.1H NMR spectrum (300 MHz, CDCl.sub.3, 298 K) of 4-((tert-butyldimethylsilyl)oxy)-2-methylbutyl)aniline.

(21) FIG. 20 is a .sup.13C NMR spectrum (75 MHz, CDCl.sub.3, 298 K) of 4-((tert-butyldimethylsilyl)oxy)-2-methylbutyl)aniline.

(22) FIG. 21 is a .sup.1H NMR spectrum (300 MHz, CDCl.sub.3, 298 K) of a mixture between N-(2-(2-bromophenyl)propyl)aniline and N-(3-(2-bromophenyl)propyl)aniline.

(23) FIG. 22 is a .sup.1H NMR spectrum (300 MHz, CDCl.sub.3, 298 K) of 1-cyclohexylimidazolidin-2-one (.sup.CyLH).

(24) FIG. 23 is a .sup.13C NMR spectrum (100 MHz, CDCl.sub.3, 298 K) of 1-cyclohexylimidazolidin-2-one (.sup.CyLH).

(25) FIG. 24 is a .sup.1H NMR spectrum (300 MHz, CDCl.sub.3, 298 K) of 1-phenylimidazolidin-2-one (.sup.PhLH).

(26) FIG. 25 is a .sup.1H NMR spectrum (75 MHz, CDCl.sub.3, 298 K) of 1-phenylimidazolidin-2-one (.sup.PhLH).

(27) FIG. 26 is a .sup.1H NMR spectrum (300 MHz, CDCl.sub.3, 298 K) of 1-(tert-butyl)imidazolidin-2-one (.sup.tBuLH).

(28) FIG. 27 is a .sup.13C NMR spectrum (75 MHz, CDCl.sub.3, 298 K) of 1-(tert-butyl)imidazolidin-2-one (.sup.tBuLH).

(29) FIG. 28 is a .sup.1H NMR spectrum (300 MHz, toluene-d.sub.8, 298 K) of Ta(CH.sub.2SiMe.sub.3).sub.3Br.sub.2.

(30) FIG. 29 is a .sup.1H NMR spectrum (300 MHz, benzene-d.sub.6, 298 K) of .sup.tBuLTa(CH.sub.2SiMe.sub.3).sub.3Cl.

(31) FIG. 30 is a .sup.13C NMR spectrum (75 MHz, benzene-d.sub.6, 298 K) of .sup.tBuLTa(CH.sub.2SiMe.sub.3).sub.3Cl.

(32) FIG. 31 is a .sup.1H NMR spectrum (400 MHz, benzene-d.sub.6, 298 K) of .sup.tBuLTa(CH.sub.2SiMe.sub.3).sub.3Br.

(33) FIG. 33 is a .sup.1H NMR spectrum (400 MHz, CDCl.sub.3, 298 K) of 3-(2,6-dimethylphenyl)-1-methyl-1-(1-phenylethyl)urea.

(34) FIG. 34 is a .sup.13C NMR spectrum (100 MHz, benzene-d.sub.6, 298 K) of 3-(2,6-dimethylphenyl)-1-methyl-1-(1-phenylethyl)urea.

(35) FIG. 35 is a .sup.1H NMR spectrum (400 MHz, CDCl.sub.3, 298 K) of 3-(2,6-dimethylphenyl)-1-isopropyl-1-phenylurea.

(36) FIG. 36 is a .sup.13C NMR spectrum (100 MHz, benzene-d.sub.6, 298 K) of 3-(2,6-dimethylphenyl)-1-isopropyl-1-phenylurea.

(37) FIG. 37 is a .sup.1H NMR spectrum (400 MHz, CDCl.sub.3, 298 K) of 1-benzhydryl-3-(2,6-dimethylphenyl)-1-methylurea.

(38) FIG. 38 is a .sup.13C NMR spectrum (100 MHz, CDCl.sub.3, 298 K) of 1-benzhydryl-3-(2,6-dimethylphenyl)-1-methylurea.

(39) FIG. 39 is a .sup.1H NMR spectrum (400 MHz, CDCl.sub.3, 298 K) of 3-(2,6-diisopropylphenyl)-1-methyl-1-(1-phenylethyl)urea.

(40) FIG. 40 is a .sup.13C NMR spectrum (100 MHz, CDCl.sub.3, 298 K) of 3-(2,6-diisopropylphenyl)-1-methyl-1-(1-phenylethyl)urea.

(41) FIG. 41 is a .sup.1H NMR spectrum (300 MHz, benzene-d.sub.6, 298 K) of LTa(CH.sub.2SiMe.sub.3).sub.3Cl.

(42) FIG. 42 is a legend of all ligands prepared and investigated in the study disclosed herein.

(43) FIG. 43 is a graph showing the effect of reaction temperature on hydroaminoalkylation for an aryl amine.

(44) FIG. 44 is a graph showing the effect of reaction temperature on hydroaminoalkylation for an alkyl amine.

(45) FIG. 45 is a graph showing the effect of precatalyst concentration on hydroaminoalkylation for an alkyl amine.

(46) FIG. 46 is a graph showing the effect of Lewis acid salts on hydroaminoalkylation for an aryl amine.

(47) FIG. 47 is a graph showing the effect of KBr on hydroaminoalkylation for an aryl amine at different temperatures.

(48) FIG. 48 is a graph showing the effect of KBr on hydroaminoalkylation for an alkyl amine.

DETAILED DESCRIPTION

Definitions

(49) “Catalyst”, as used herein, refers to a chemical compound that accelerates a chemical reaction without itself being affected. “Catalyst” may be used interchangeably with terms such as “pre-catalyst”, “catalyst system”, or “catalytic system”. “Catalyst”, as used herein, includes catalytic intermediates or species formed in situ.

(50) “Group 5 metal” as used herein, refers to the d-electron comprising transition metals listed in the periodic table of the elements as group 5, including transition metals vanadium (V), niobium (Nb), tantalum (Ta), and dubnium (Db).

(51) “Hydroaminoalkylation”, as used herein, refers to a reaction between a secondary amine containing moiety and an olefin. A catalyst may often be used to promote such reaction.

(52) “Secondary amine”, as used herein, refers to an amine in which the amino group is directly bonded to two C-atoms of any hybridization. The two C-atoms in α-position to the N-atom may be sp.sup.3 hybridized.

(53) “Olefin” or “alkene”, as used herein, refers to an unsaturated hydrocarbon containing one or more pairs of C-atoms linked by a double bond.

(54) “TOF”, as used herein, refers to “turnover frequency”.

(55) Throughout this specification, unless the context requires otherwise, the words “comprise”, “comprising” and the like, are to be construed in an inclusive sense as opposed to an exclusive sense, that is to say, in the sense of “including, but not limited to”.

(56) This disclosure relates to the discovery that rapid C—H alkylation of unprotected secondary arylamines with unactivated alkenes can be achieved with metal complex catalysts comprising a combination of a tantalum (Ta) organometallic reagent (e.g. Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2) and a ureate N,O chelating-ligand salt.

(57) Materials and Methods

(58) The procedures described herein are given for the purposes of example and illustration only and should not be considered to limit the spirit or scope of the invention.

(59) 1. Materials

(60) All reactions were performed under a N.sub.2 atmosphere using Schlenk or glovebox techniques, unless otherwise stated. TaCl.sub.5 (Strem), Ta(NMe.sub.2).sub.5 (Strem), and (chloromethyl)trimethylsilane (Sigma) were used as received. NaN(SiMe.sub.3).sub.2 (Sigma) was recrystallized from a hot toluene solution before use. All amines and alkenes were commercially available, dried over CaH.sub.2 and distilled and degassed prior to use in catalytic experiments. [Ta(NMe.sub.2).sub.3Cl.sub.2].sub.2, TaMe.sub.3Cl.sub.2, Ta(CH.sub.2CMe.sub.3).sub.3Cl.sub.2, and Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2, were synthesized according to literature protocols (Chem. Int. Ed. 48, 4892-4894; Synthesis 46, 2884-2896; Chem. Res 48: 2576-2586; Inorg. Chem. 20: 1859-1866; J. Am. Chem. Soc. 100: 2389-2399; Dalton Trans. 40, 7777-7782). All glassware was dried in a 180° C. oven overnight before use. Toluene, hexanes and Et.sub.2O were dried over an activated alumina column and stored over activated molecular sieves (4 Å). d.sub.6-Benzene and d.sub.8-toluene were dried over sodium/ketyl and distilled prior to use. Experiments conducted on NMR tube scale were performed in J. Young NMR tubes (8″×5 mm) sealed with screw-type Teflon caps.

(61) 2. Instrumentation

(62) .sup.1H and .sup.13C NMR spectra were recorded on Bruker 300 MHz, or 400 MHz, Avance spectrometers at ambient temperature. Chemical shifts (δ) are given relative to the corresponding residual protio solvent and are reported in parts per million (ppm). Coupling constants J are given in Hertz (Hz). The following abbreviations are used to indicate signal multiplicity: s=singlet, d=doublet, t=triplet, q=quartet, m=multiplet, and br=broad. Assignment of the signals was carried out using 1D (.sup.1H, .sup.13C{.sup.1H}) and 2D (COSY, HSQC and HMBC) NMR experiments.

(63) 3. Synthesis

(64) 3.1 Proligands

(65) The synthesis of proligands is generally discussed below, with reference to particular exemplified proligands. FIG. 42 summarizes the proligands synthesized and disclosed herein.

(66) General Procedure for the Synthesis of Urea Proligands:

(67) Urea proligands were prepared following a modified literature procedure.sup.3 in which the aniline (1 equiv) was dissolved in DCM and the solution was cooled to 0° C. Triphosgene (0.35 equiv) was added in one portion. The solution was stirred for five minutes after which N,N-diisopropylethylamine (2 equiv) was added and the cold bath removed. The solution was stirred for 1 hour and then piperidine (1 equiv) and a second portion of N,N-diisopropylethylamine (1 equiv) were added. The solution was stirred for an additional hour, and then diluted with 1M HCl. The organic phase was washed three times with 1M HCl dried over MgSO.sub.4, filtered, and concentrated by rotary evaporation.

Synthesis of 3-(2,6-dimethylphenyl)-1,1-diphenylurea

(68) ##STR00015##

(69) Prepared following the general procedure outlined above. Recrystallization provided the desired compound as a white solid (1.2 g, Unoptimized Synthesis): .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 7.42-7.38 (overlapping m, 8H, o-C.sub.6H.sub.5 and m-C.sub.6H.sub.5), 7.29-7.18 (m, 2H, p-C.sub.6H.sub.5), 7.05 (s, 3H, 2,6-Me.sub.2C.sub.6H.sub.3), 5.79 (NH), 2.27 (s, 6H, CH.sub.3) ppm. .sup.13C NMR (CDCl.sub.3, 75 MHz, 298 K): δ 153.94 (C═O), 142.72 (i-C.sub.6H.sub.5), 135.68 (o-C.sub.6H.sub.3), 134.56 (i-C.sub.6H.sub.3), 129.53 (m-C.sub.6H.sub.5), 128.12 (m-C.sub.6H.sub.3), 127.28 (o-C.sub.6H.sub.5), 126.85 (p-C.sub.6H.sub.5), 126.40 (p-C.sub.6H.sub.3), 18.62 (CH.sub.3) ppm.

(70) A .sup.1H NMR spectrum (300 MHz, CDCl.sub.3, 298 K) of 3-(2,6-dimethylphenyl)-1,1-diphenylurea is shown in FIG. 1. A .sup.13C NMR spectrum (75 MHz, CDCl.sub.3, 298 K) of 3-(2,6-dimethylphenyl)-1,1-diphenylurea is shown in FIG. 2.

Synthesis of 3-(2,6-dimethylphenyl)-1-isopropyl-1-phenylurea

(71) ##STR00016##

(72) Prepared following the general procedure outlined above. Recrystallization provided the desired compound as a white solid (1.1 g, Unoptimized Synthesis): .sup.1H NMR (CDCl.sub.3, 400 MHz, 298 K): δ 7.61-7.28 (overlapping m, 5H, o,m,p-C.sub.6H.sub.5), 6.99 (s, 3H, C.sub.6H.sub.3), 5.24 (NH), 4.96 (hept, .sup.3J.sub.H—H=6.5 Hz, 1H, CH(CH.sub.3).sub.2), 2.19 (s, 6H, 2,6-(CH.sub.3).sub.2C.sub.6H.sub.3), 1.14 (d, .sup.3J.sub.H—H=6.2 Hz, 6H, CH(CH.sub.3).sub.2) ppm. .sup.13C NMR (CDCl.sub.3, 101 MHz, 298 K): 154.62 (C═O), 138.17 (i-C.sub.6H.sub.5), 135.71 (o-C.sub.6H.sub.3), 135.18 (i-C.sub.6H.sub.3), 131.21 (m-C.sub.6H.sub.3), 129.83 (o-C.sub.6H.sub.5), 128.66 (p-C.sub.6H.sub.5), 127.94 (m-C.sub.6H.sub.3), 126.38 (p-C.sub.6H.sub.3), 46.58 (CH(CH.sub.3).sub.2), 21.65 (CH(CH.sub.3).sub.3), 18.47 (2,6-(CH.sub.3).sub.2C.sub.6H.sub.3) ppm.

(73) A .sup.1H NMR spectrum (300 MHz, CDCl.sub.3, 298 K) of 3-(2,6-dimethylphenyl)-1-isopropyl-1-phenylurea is shown in FIG. 3. A .sup.13C NMR spectrum (75 MHz, CDCl.sub.3, 298 K) of 3-(2,6-dimethylphenyl)-1-isopropyl-1-phenylurea.

(74) Cyclic Ureate Ligands

Synthesis and Characterization of Cyclic Ureate Proligands

(75) ##STR00017##

Synthesis of 1-cyclohexylimidazolidin-2-one (.SUP.Cy.LH)

(76) ##STR00018## A solution 2-chloroethyl isocyanate (1.11 g, 10.5 mmol) in THF (50 mL) was added dropwise to a stirring solution of cyclohexylamine (0.99 g, 10 mmol) in THF (20 mL) at room temperature. The resulting reaction mixture was treated with NaH (0.24 g, 10 mmol) under an inert atmosphere and stirred at room temperature overnight under an inert atmosphere. The mixture was treated with saturated NH.sub.4Cl (100 mL) and EtOAc (200 mL). The organic layer was separated and the aqueous layer was extracted with EtOAc (3×50 mL). The combined organic fractions were dried over Na.sub.2SO.sub.4 and concentrated under vacuum to form a colorless suspension in EtOAc. The reaction mixture was filtered and the resulting solid was dried to form the desired product. Yield (0.44 g, 27%). .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 5.41 (br s, 1H, NH), 3.77-3.58 (m, 1H, NCH), 3.43 (s, 4H, CH.sub.2CH.sub.2NH), 1.92-1.52 (m, 11H, HNCH.sub.2) ppm. .sup.13C NMR (CDCl.sub.3, 75 MHz, 298 K): δ 162.52 (C═O), 40.71 (.sup.tBuNCH.sub.2), 51.15 (CH), 38.76 (HNCH.sub.2), 30.39 (.sup.CyCH.sub.2), 25.64 (.sup.CyCH.sub.2) ppm. HRMS (ESI): m/z calcd for C.sub.9H.sub.16N.sub.2ONa [M+Na.sup.+]: 191.1160. Found: 191.1159.

(77) FIG. 22 is a .sup.1H NMR spectrum (300 MHz, CDCl.sub.3, 298 K) of 1-cyclohexylimidazolidin-2-one (.sup.cyLH). FIG. 23 is a .sup.13C NMR spectrum (100 MHz, CDCl.sub.3, 298 K) of 1-cyclohexylimidazolidin-2-one (.sup.CyLH).

Synthesis of 1-phenylimidazolidin-2-one (.SUP.Ph.LH)

(78) ##STR00019##

(79) A solution 2-chloroethyl isocyanate (1.05 g, 10 mmol) in THF (50 mL) was added dropwise to a stirring solution of phenylamine (0.93 g, 10 mmol) in THF (20 mL) at −20° C. The solution was brought to room temperature overnight. The resulting reaction mixture was treated with NaH (0.24 g, 10 mmol) under an inert atmosphere and stirred at room temperature overnight. The mixture was treated with saturated NH.sub.4Cl (100 mL) and EtOAc (200 mL). The organic layer was separated and the aqueous layer was extracted with EtOAc (3×50 mL). The combined organic fractions were dried over Na.sub.2SO.sub.4 and concentrated under vacuum to form a colorless suspension in EtOAc. The reaction mixture was filtered and the resulting solid was dried to form the desired product. Yield (0.42 g, 26%). .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 7.58 (d, 2H, J.sub.H—H=8.2 Hz, m-C.sub.6H.sub.5), 7.38-7.29 (m, 2H, o-C.sub.6H.sub.5), 7.05 (t, 2H, J.sub.H—H=7.2 Hz, p-C.sub.6H.sub.5), 4.00-3.84 (m, 2H, .sup.PhNCH.sub.2), 3.65-3.48 (m, 2H, HNCH.sub.2) ppm. .sup.13C NMR (CDCl.sub.3, 75 MHz, 298 K): δ 160.27 (C═O), 140.18 (C.sub.6H.sub.5), 128.92 (C.sub.6H.sub.5), 122.83 (C.sub.6H.sub.5), 118.09 (C.sub.6H.sub.5), 45.49 (.sup.PhNCH.sub.2), 37.70 (HNCH.sub.2) ppm. HRMS (ESI): m/z calcd for C.sub.9H.sub.10N.sub.2ONa [M+Na.sup.+]: 185.0691. Found: 185.0691.

(80) FIG. 24 is a .sup.1H NMR spectrum (300 MHz, CDCl.sub.3, 298 K) of 1-phenylimidazolidin-2-one (.sup.PhLH). FIG. 25 is a .sup.1H NMR spectrum (75 MHz, CDCl.sub.3, 298 K) of 1-phenylimidazolidin-2-one (.sup.PhLH).

Synthesis of 1-(tert-butyl)imidazolidin-2-one (.SUP.tBu.LH)

(81) ##STR00020##

(82) A solution 2-chloroethyl isocyanate (6.80 g, 64 mmol) in THF (50 mL) was added dropwise to a stirring solution of tertbutylamine (4.28 g, 58.5 mmol) in THF (20 mL) at −20° C. The solution was brought to room temperature overnight. The resulting reaction mixture was treated with NaH (6.8 g, 283 mmol) under an inert atmosphere and heated at 65° C. overnight under an inert atmosphere. The mixture was brought to dryness and treated with saturated NH.sub.4Cl (100 mL) and EtOAc (200 mL). The organic layer was separated and the aqueous layer was extracted with EtOAc (3×50 mL). The combined organic fractions were dried over Na.sub.2SO.sub.4 and brought to dryness under vacuum forming a yellow oil. Hexanes (5 mL) were then added resulting with the formation of a solid at the bottom of the round bottom flask. The mother liquor was removed by filtration. This process was repeated 3 more times and the combined hexane solutions (fraction 1) were stored at −30° C. overnight, while the solid (fraction 2) was also kept. Storing the combined hexane solutions (fraction 1) at low temperatures resulted in the formation of colorless crystals that were later filtered and dried in vacuo to afford 350 mg of pure product. The solid from fraction 2 was sublimed at 100° C. under vacuum to afford a waxy solid on the cold finger. The resulting waxy solid was washed with hexanes (2×4 mL) to afford 770 mg of pure product. Total yield: 1.12 g (13%). .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 4.37 (br s, 1H, NH), 3.49-3.40 (m, 2H, .sup.tBuNCH.sub.2), 3.33-3.23 (m, 2H, HNCH.sub.2), 1.36 (s, 9H, C(CH.sub.3).sub.3) ppm. .sup.13C NMR (CDCl.sub.3, 75 MHz, 298 K): δ 163.15 (C═O), 52.96 (C(CH.sub.3).sub.3), 43.73 (.sup.TbUNCh.sub.2), 38.13 (HNCH.sub.2), 27.67 (C(CH.sub.3).sub.3) ppm. HRMS (ESI): m/z calcd for C.sub.7H.sub.14N.sub.2O [M+Na.sup.+]: 165.10039. Found: 165.1001. Anal. Calcd. for C.sub.7H.sub.14N.sub.2O: C, 59.12; H, 9.92; N, 19.70; Found: C, 59.12; H, 10.29; N, 19.71.

(83) FIG. 26 is a .sup.1H NMR spectrum (300 MHz, CDCl.sub.3, 298 K) of 1-(tert-butyl)imidazolidin-2-one (.sup.tBuLH). FIG. 27 is a .sup.13C NMR spectrum (75 MHz, CDCl.sub.3, 298 K) of 1-(tert-butyl)imidazolidin-2-one (.sup.tBuLH).

Synthesis of Cyclic Ureate Ligand Salts

(84) General Procedure for the Synthesis of Ligand Salts .sup.xLH (X=Me,Cy, pH, .sup.tBu):

(85) NaN(SiMe.sub.3).sub.2 (1 equiv.) and the corresponding proteoligand (1 equiv.) were mixed in toluene (˜5 mL) and stirred overnight at room temperature. The volatiles were then removed at low pressure and the resulting solid was thoroughly stripped with hexanes (3×5 mL) and dried to give the sodium salt in moderate to quantitative yields as a colorless powder. The resulting ligand salts were used directly without further purification via storage in a glove box. Except in the case of .sup.DippLH, NMR characterization was precluded due to poor solubility in common NMR solvents (e.g. d.sub.6-benzene or d.sub.8-toluene).

Synthesis of sodium 3-methyl-2-oxoimidazolidin-1-ide (.SUP.Me.L.SUP.−.Na.SUP.+.)

(86) ##STR00021##

(87) Prepared following the general procedure outlined above: .sup.MeLH (197 mg, 1.97 mmol) and NaN(SiMe.sub.3).sub.2 (361 mg, 1.97 mmol). Yield (163 mg, 68%).

Synthesis of sodium 3-cyclohexyl-2-oxoimidazolidin-1-ide (.SUP.Cy.L.SUP.−.Na.SUP.+.)

(88) ##STR00022##

(89) Prepared following the general procedure outlined above: .sup.cyLH (100 mg, 0.59 mmol) and NaN(SiMe.sub.3).sub.2 (109 mg, 0.59 mmol). Yield (107 mg, 95%).

Synthesis of sodium 2-oxo-3-phenylimidazolidin-1-ide (.SUP.Ph.L.SUP.−.Na+)

(90) ##STR00023##

(91) Prepared following the general procedure outlined above: .sup.PhLH (150 mg, 0.93 mmol) and NaN(SiMe.sub.3).sub.2 (170 mg, 0.93 mmol). Yield (140 mg, 82%).

Synthesis of sodium 3-(tert-butyl)-2-oxoimidazolidin-1-ide (.SUP.tBu.L.SUP.−.Na.SUP.+.)

(92) ##STR00024##

(93) Prepared following the general procedure outlined above: .sup.tBuL.sup.−Na.sup.+ (230 mg, 1.62 mmol) and NaN(SiMe.sub.3).sub.2 (297 g, 1.62 mmol). Yield (265 mg, 99%).

(94) Acyclic Ureate Ligands

(95) Synthesis and Characterization of Proteoligands

(96) General procedure for the synthesis of urea based proteoligands: Prepared following a modified literature procedure in which a chosen primary amine (1 equiv.) was dissolved in dichloromethane and the solution was cooled to 0° C. Triphosgene (0.35 equiv.) was added in portions as a solid. The solution was stirred for five minutes after which N,N-diisopropylethylamine DIPEA (3 equiv.) was added and the cold bath removed. The solution was stirred for 1 hour and then the appropriate amine (1 equiv.) and a second portion of DIPEA (1 equiv.) was added. The solution was stirred for an additional hour, and then diluted with 3M HCl. The organic phase was washed three times with 1M HCl dried over MgSO.sub.4, filtered, and concentrated by rotary evaporation to give the crude product.

Synthesis of 3-(2,6-dimethylphenyl)-1-methyl-1-(1-phenylethyl)urea

(97) ##STR00025##

(98) Prepared following the general procedure outlined above: 2,6-dimethylaniline (2.25 g, 18.5 mmol), triphosgene (1.81 g, 6.10 mmol), DIPEA (7.2 g, 55.5 mmol), N-methyl-1-phenylethan-1-amine (2.5 g, 18.5 mmol). Recrystallization from a concentrated ethyl acetate solution provided the desired compound as a white solid (3.48 g, 66.9%): .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 7.41-7.26 (overlapping m, 5H, o-C.sub.6H.sub.5 m-C.sub.6H.sub.5, and p-C.sub.6H.sub.5), 7.04 (s, 3H, m-C.sub.6H.sub.5, and p-C.sub.6H.sub.5), 5.86 (br s, 1H, NH), 5.64-5.57 (q, 1H, CHCH.sub.3), 2.79 (s, 3H, CH.sub.3), 2.19 (s, 6H, 2,6-(CH.sub.3).sub.2C.sub.6H.sub.3) ppm. .sup.13C NMR (CDCl.sub.3, 75 MHz, 298 K): δ 156.31 (C═O), 141.79, 135.58, 135.33, 128.64, 128.07, 127.28, 126.88, 126.34, 52.80, 29.53, 18.43, 17.02 ppm. HRMS (ESI): m/z calcd for C.sub.18H.sub.23N.sub.2O [M+H.sup.+]: 283.1810. Found: 283.1809.

(99) FIG. 33 is a .sup.1H NMR spectrum (400 MHz, CDCl.sub.3, 298 K) of 3-(2,6-dimethylphenyl)-1-methyl-1-(1-phenylethyl)urea. FIG. 34 is a .sup.13C NMR spectrum (100 MHz, benzene-d.sub.6, 298 K) of 3-(2,6-dimethylphenyl)-1-methyl-1-(1-phenylethyl)urea.

Synthesis of 3-(2,6-dimethylphenyl)-1-isopropyl-1-phenylurea

(100) ##STR00026##

(101) Prepared following the general procedure outlined above: 2,6-dimethylaniline (1.5 g, 20.5 mmol), triphosgene (2.02 g, 7.41 mmol), DIPEA (7.95 g, 61.5 mmol), N-isopropylaniline (2.5 g, 20.5 mmol). Recrystallization from a concentrated ethyl acetate solution provided the desired compound as a white solid (3.20 g, 65%): .sup.1H NMR (CDCl.sub.3, 400 MHz, 298 K): δ 7.05 (s, 3H, o,m,p-C.sub.6H.sub.5), 5.69 (br s, 1H, NH), 4.56-4.49 (m, 1H, CH(CH.sub.3).sub.2), 2.86 (s, 3H, CH.sub.3), 2.24 (s, 6H, 2,6-(CH.sub.3).sub.2C.sub.6H.sub.3), 1.17 (d, J.sub.H—H=1.7 Hz, 6H, CH(CH.sub.3).sub.2) ppm. .sup.13C NMR (CDCl.sub.3, 101 MHz, 298 K): δ 156.00 (C═O), 135.70, 135.57, 128.20, 126.40, 45.89, 27.45, 20.21, 18.56 ppm. HRMS (ESI): m/z calcd for C.sub.13H.sub.21N.sub.2O [M+H.sup.+]: 221.1654. Found: 221.1656.

(102) FIG. 35 is a .sup.1H NMR spectrum (400 MHz, CDCl.sub.3, 298 K) of 3-(2,6-dimethylphenyl)-1-isopropyl-1-phenylurea. FIG. 36 is a .sup.13C NMR spectrum (100 MHz, benzene-d.sub.6, 298 K) of 3-(2,6-dimethylphenyl)-1-isopropyl-1-phenylurea.

Synthesis of 1-benzhydryl-3-(2,6-dimethylphenyl)-1-methylurea

(103) ##STR00027##

(104) Prepared following the general procedure outlined above: 2,6-dimethylaniline (307 mg, 2.53 mmol), triphosgene (250.2 mg, 0.843 mmol), DIPEA (981 mg, 7.59 mmol), N-methyl-1,1-diphenylmethanamine (500 mg, 2.53 mmol). Recrystallization from a concentrated ethyl acetate solution provided the desired compound as a white solid (750 mg, 86%): .sup.1H NMR (CDCl.sub.3, 400 MHz, 298 K): δ 7.41-7.27 (overlapping m, 10H, o,m,p-C.sub.6H.sub.5), 7.04 (s, 3H, m,p-C.sub.6H.sub.5), 6.70 (s, 1H, NHCH), 5.78 (br s, 1H, NH), 2.88 (s, 3H, CH.sub.3), 2.16 (s, 6H, 2,6-(CH.sub.3).sub.2C.sub.6H.sub.3) ppm. .sup.13C NMR (CDCl.sub.3, 101 MHz, 298 K): δ 156.57 (C═O), 139.66, 135.47, 135.30, 128.80, 128.77, 128.25, 127.80, 126.49, 63.30, 32.05, 28.48 ppm. HRMS (ESI): m/z calcd for C.sub.23H.sub.25N.sub.2O [M+H.sup.+]: 345.1967 Found: 345.1964.

(105) FIG. 37 is a .sup.1H NMR spectrum (400 MHz, CDCl.sub.3, 298 K) of 1-benzhydryl-3-(2,6-dimethylphenyl)-1-methylurea. FIG. 38 is a .sup.13C NMR spectrum (100 MHz, CDCl.sub.3, 298 K) of 1-benzhydryl-3-(2,6-dimethylphenyl)-1-methylurea.

Synthesis of 3-(2,6-diisopropylphenyl)-1-methyl-1-(1-phenylethyl)urea

(106) ##STR00028##

(107) Prepared following the general procedure outlined above: 2,6-dimethylaniline (1.32 g, 7.40 mmol), triphosgene (724 mg, 2.44 mmol), DIPEA (2.87 g, 22.2 mmol), N-methyl-1,1-diphenylmethanamine (1.0 g, 7.40 mmol). Recrystallization from a concentrated ethyl acetate solution provided the desired compound as a white solid (1.81 g, 72.3%): .sup.1H NMR (CDCl.sub.3, 400 MHz, 298 K): δ 7.51-7.50 (overlapping m, 4H), 7.45-7.39 (overlapping m, 2H), 7.37-7.35 (m, 1H), 7.28 (m, 1H), 5.78-5.72 (overlapping m, 2H), 3.22-3.12 (m, 2H, CH(CH.sub.3).sub.2), 3.00 (s, 3H, CH.sub.3), 1.72 (s, 3H, CH.sub.3), 1.31 (s, 12H, CH(CH.sub.3).sub.2) ppm. .sup.13C NMR (CDCl.sub.3, 101 MHz, 298 K): δ 157.22 (C═O), 146.52, 142.12, 132.80, 128.73, 127.63, 127.41, 126.95, 123.36, 52.99, 29.82, 28.79, 23.81 ppm. HRMS (ESI): m/z calcd for C.sub.22H.sub.31N.sub.2O [M+H.sup.+]: 339.2437. Found: 339.2444.

(108) FIG. 39 is a .sup.1H NMR spectrum (400 MHz, CDCl.sub.3, 298 K) of 3-(2,6-diisopropylphenyl)-1-methyl-1-(1-phenylethyl)urea. FIG. 40 is a .sup.13C NMR spectrum (100 MHz, CDCl.sub.3, 298 K) of 3-(2,6-diisopropylphenyl)-1-methyl-1-(1-phenylethyl)urea.

Synthesis of Ta(CH.SUB.2.SiMe.SUB.3.).SUB.3.Br.SUB.2

(109) A solution of Zn(CH.sub.2SiMe.sub.3).sub.2 (0.64 g, 2.67 mmol) in hexanes (20 mL) was added to a suspension of TaBr.sub.5 (1.00 g, 1.72 mmol) in hexanes (10 mL). The reaction mixture was stirred at room temperature overnight forming a colorless precipitate. The following day, the solution was filtered and concentrated in vacuo to afford the formation of the title product as yellow powder. Yield (0.73 g, 71%). .sup.1H NMR (toluene-d.sub.8, 300 MHz, 298 K): δ 2.11 (s, 6H, CH.sub.2), 0.29 (s, 27H, SiCH.sub.3) ppm.

(110) 3.3 Ligand Salts

(111) General procedure for the synthesis of ligand salts NaN(SiMe.sub.3).sub.2 (1 equiv.) was added in portions to a suspension of the corresponding proteo-ligand (1 equiv.) in Et.sub.2O (˜10 mL) and stirred overnight at room temperature. The volatiles were then removed at low pressure and the resulting solid was thoroughly washed with hexanes (3×5 mL) and dried to give the sodium salt as a colorless powder. Salts were used directly without further characterization.

(112) ##STR00029##

Synthesis and Characterization of Tantalum Based Ureate Complexes

(113) ##STR00030##

(114) FIG. 28 is a .sup.1H NMR spectrum (300 MHz, toluene-d.sub.8, 298 K) of Ta(CH.sub.2SiMe.sub.3).sub.3Br.sub.2.

Synthesis of .SUP.tBu.LTa(CH.SUB.2.SiMe.SUB.3.).SUB.3.Cl

(115) ##STR00031##

(116) A suspension of .sup.tBuL.sup.−Na.sup.+ (71 mg, 0.43 mmol) in toluene (3 mL) was added dropwise at room temperature to a solution of Ta(CH.sub.2SiMe.sub.3)Cl.sub.2 (200 mg, 0.39 mmol) in toluene (3 mL). The reaction mixture was stirred for 30 min. The volatiles were then removed in vacuo and the title complex was extracted with hexanes (3×5 mL) and filtered over celite. The resulting organic solution was concentrated to approx. 3 mL and stored in a freezer at −30° C. A large crop of crystals were formed overnight which were further dried affording the title compound as pale yellow crystals. Yield (150 mg, 62%). .sup.1H NMR (benzene-d.sub.6, 300 MHz, 298 K): δ 3.36-3.23 (m, 2H, NCH.sub.2), 2.75-2.62 (m, 2H, NCH.sub.2), 1.57 (s, 6H, CH.sub.2SiMe.sub.3), 1.06 (s, 9H, NC(CH.sub.3).sub.3, 0.36 (s, 27H, SiCH.sub.3) ppm. .sup.13C NMR (benzene-d.sub.6, 75 MHz, 298 K): δ 171.36 (C═O), 90.19 (CH.sub.2SiMe.sub.3), 53.68 (NC(CH.sub.3).sub.3), 45.38 (NCH.sub.2), 44.41 (NCH.sub.2), 27.96 (NC(CH.sub.3).sub.3), 2.79 (SiCH.sub.3) ppm. LRMS (ESI): m/z: 531 (M-CH.sub.2SiMe.sub.3-H.sup.+), 443 (M-2CH.sub.2SiMe.sub.3-2H.sup.+). Anal. Calcd. for C.sub.19H.sub.47ClN.sub.2OSi.sub.3Ta: C, 36.79; H, 7.64; N, 4.52; Found: C, 36.44; H, 7.69; N, 4.59.

(117) FIG. 29 is a .sup.1H NMR spectrum (300 MHz, benzene-d.sub.6, 298 K) of .sup.tBuLTa(CH.sub.2SiMe.sub.3).sub.3Cl. FIG. 30 is a .sup.13C NMR spectrum (75 MHz, benzene-d.sub.6, 298 K) of .sup.tBuLTa(CH.sub.2SiMe.sub.3).sub.3Cl.

Synthesis of .SUP.tBu.LTa(CH.SUB.2.SiMe.SUB.3.).SUB.3.Br

(118) ##STR00032##

(119) A suspension of .sup.tBuL.sup.−Na.sup.+ (30 mg, 0.19 mmol) in toluene (3 mL) was added dropwise at room temperature to a solution of Ta(CH.sub.2SiMe.sub.3)Cl.sub.2 (106 mg, 0.18 mmol) in toluene (3 mL). The reaction mixture was stirred for 30 min. The volatiles were then removed in vacuo and the title complex was extracted with hexanes (3×5 mL) and filtered over celite. The resulting organic solution was concentrated to approx. 3 mL and stored in a freezer at −30° C. A large crop of crystals were formed overnight which were further dried affording the title compound as pale yellow crystals. Yield (35 mg, 30%). .sup.1H NMR (benzene-d.sub.6, 400 MHz, 298 K): δ 3.31-3.24 (m, 2H, NCH.sub.2), 2.72-2.65 (m, 2H, NCH.sub.2), 1.62 (s, 6H, CH.sub.2SiMe.sub.3), 1.05 (s, 9H, NC(CH.sub.3).sub.3, 0.37 (s, 27H, SiCH.sub.3) ppm. .sup.13C NMR (benzene-d.sub.6, 75 MHz, 298 K): δ 171.18 (C═O), 94.33 (CH.sub.2SiMe.sub.3), 53.78 (NC(CH.sub.3).sub.3), 45.34 (NCH.sub.2), 44.16 (NCH.sub.2), 27.96 (NC(CH.sub.3).sub.3), 2.91 (SiCH.sub.3) ppm.

(120) FIG. 31 is a .sup.1H NMR spectrum (400 MHz, benzene-d.sub.6, 298 K) of .sup.tBuLTa(CH.sub.2SiMe.sub.3).sub.3Br. FIG. 32 is a .sup.13C NMR spectrum (100 MHz, benzene-d.sub.6, 298 K) of .sup.tBuLTa(CH.sub.2SiMe.sub.3).sub.3Br.

Synthesis and Characterization of Tantalum Based Ureate Complexes

Synthesis of LTa(CH.SUB.2.SiMe.SUB.3.).SUB.3.Cl

(121) ##STR00033##

(122) A suspension of L.sup.−Na.sup.+ (206 mg, 0.81 mmol) in toluene (5 mL) was added dropwise at room temperature to a solution of Ta(CH.sub.2SiMe.sub.3)Cl.sub.2 (378 mg, 0.736 mmol) in toluene (6 mL). The reaction mixture was stirred for 30 min. The volatiles were then removed in vacuo and the title complex was extracted with hexanes (3×5 mL) and filtered over celite. The resulting organic solution was concentrated to approx. 3 mL and stored in a freezer at −30° C. Over a week period, a large amount of solid precipitated. The mixture was then filtered and the resulting solid was dried in vacuo to form the desired complex. Yield (370 mg, 71%). .sup.1H NMR (benzene-d.sub.6, 300 MHz, 298 K): δ 6.92-6.80 (m, 3H, C.sub.6H.sub.3), 3.52-3.85 (m, 2H, CH.sub.2), 2.21 (s, 6H, CH.sub.2SiMe.sub.3), 1.41 (s, 6H, CH.sub.3), 0.39 (s, 27H, SiCH.sub.3) ppm.

(123) FIG. 41 is a .sup.1H NMR spectrum (300 MHz, benzene-d.sub.6, 298 K) of LTa(CH.sub.2SiMe.sub.3).sub.3Cl.

3.4 Hydroaminoalkylation Reaction:

General Procedure for Hydroaminoalkylation Reaction:

(124) Solid tantalum precursor (0.0025 mmol) was weighed into a vial, followed by addition of the chosen ligand salt (0.025 mmol) d.sub.8-toluene (0.3 g) was added, and the resultant mixture was left for 15 minutes. A chosen amine substrate was then added (0.5 mmol), followed by the alkene (0.5 mmol). The resultant reaction mixture was transferred into a J. Young NMR tube and the vial was rinsed with an additional 0.2 g of d.sub.8-toluene. An initial .sup.1H NMR spectrum was recorded and the sample was added to a pre-heated oil bath. All conversion values were determined by .sup.1H NMR spectroscopy. After removal of all reaction solvent, pentane was added to the reaction mixture and a white precipitate was formed instantaneously. Residual tantalum salts and proteo-ligands were then removed by filtering the pentane solution at −80° C. Unreacted amine or alkene starting materials were removed at 40° C. under low pressure. In all cases, .sup.1H NMR spectroscopy still showed the presence of proteo-ligands in low amounts (2-4%), which can be entirely removed by column chromatography. N-(2-propylhexyl)aniline and N-(2-ethylpentyl)aniline showed signs of decomposition while heated under vacuum, and therefore must be purified by column chromatography.

N-(2-methyloctyl)aniline:

(125) ##STR00034##

(126) N-methylaniline (54 mg, 0.5 mmol), 1-octene (0.056 g, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L4 (8 mg, 0.025 mmol). Reaction time: 2 h. Yield 88%. .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 7.24-7.16 (m, 2H, bum-C.sub.6H.sub.5), 6.75-6.67 (m, 1H, p-C.sub.6H.sub.5), 6.67-6.60 (m, 2H, o-C.sub.6H.sub.5), 3.69 (br s, 1H, NH), 3.08 (dd, J.sub.H—H=12.8, 5.8 Hz, 1H, NC(H)H), 2.91 (dd, J.sub.H—H=12.2, 7.3 Hz, 1H, NC(H)H), 1.86-1.68 (m, 1H, 1.53-1.14 (overlapping m, 10H, CH.sub.2), 1.00 (d, J.sub.H—H=6.6 Hz, 3H, CHCH.sub.3), 0.97-0.89 (t, J.sub.H—H=6.1 Hz, 3H, CH.sub.2CH.sub.3) ppm. The chemical shifts for the title compound match those reported by Hartwig et al.

N-(cyclooctylmethyl)aniline

(127) ##STR00035##

(128) N-methylaniline (54 mg, 0.5 mmol), cyclooctene (55 mg, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L5 (8 mg, 0.025 mmol). Reaction time: 6 h. Yield 83%. .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 7.20 (dd, J.sub.H—H=8.5, 7.4 Hz, 2H, m-C.sub.6H.sub.5), 6.70 (t, J.sub.H—H=6.7 Hz, 1H, p-C.sub.6H.sub.5), 6.62 (dd, J.sub.H—H=8.5, 0.9 Hz, 2H, o-C.sub.6H.sub.5), 3.71 (br s, 1H, NH), 2.08 (d, J.sub.H—H=6.8 Hz, NCH.sub.2), 1.92-1.27 (overlapping m, 13H, CH.sub.2 and CH) ppm.

4-methoxy-N-(2-methyloctyl)aniline

(129) ##STR00036##

(130) 4-methoxy-N-methylaniline (96 mg, 0.5 mmol), 1-octene (0.056 g, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L4 (8 mg, 0.025 mmol). Reaction time: 2 h. Yield 77%. .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 6.84-6.74 (m, 2H, m-C.sub.6H.sub.4), 6.63-6.55 (m, 2H, o-C.sub.6H.sub.4), 3.76 (s, 3H, OCH.sub.3), 3.38 (br s, 1H, NH), 3.02 (dd, J.sub.H—H=5.8, 12.1 Hz, 1H, NC(H)H), 3.02 (dd, J.sub.H—H=7.8, 12.1 Hz, 1H, NC(H)H), 1.82-1.64 (m, 1H, CH), 1.55-1.05 (m, 10H, CH.sub.2), 0.98 (d, J.sub.H—H=6.6 Hz, 3H, CHCH.sub.3), 0.91 (t, J.sub.H—H=6.7 Hz, 3H, CH.sub.2CH.sub.3) ppm. The chemical shifts for the title compound match those previously reported in the literature.

4-bromo-N-(2-methyloctyl)aniline

(131) ##STR00037##

(132) 4-bromo-N-methylaniline (93 mg, 0.5 mmol), 1-octene (0.056 g, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L4 (8 mg, 0.025 mmol). Reaction time: 2 h. Yield 86%. .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 7.23 (d, J.sub.H—H=8.7 Hz, 2H, m-C.sub.6H.sub.4), 6.48 (d, J.sub.H—H=8.9 Hz, 2H, o-C.sub.6H.sub.4), 3.92 (br s, 1H, NH), 3.01 (dd, J.sub.H—H=5.9, 12.2 Hz, 1H, NC(H)H), 2.84 (dd, J.sub.H—H=7.1, 12.1 Hz, 1H, NC(H)H), 1.78-1.65 (m, 1H, CH), 1.51-1.08 (m, 10H, CH.sub.2), 0.96 (d, J.sub.H—H=6.6 Hz, 3H, CHCH.sub.3), 0.89 (t, J.sub.H—H=6.9 Hz, 3H, CH.sub.2CH.sub.3) ppm. .sup.13C NMR (CDCl.sub.3, 75 MHz, 298 K): δ 148.51 (i-C.sub.6H.sub.4), 129.34 (m-C.sub.6H.sub.4), 117.24 (p-C.sub.6H.sub.4), 112.87 (o-C.sub.6H.sub.4), 48.11, 47.99, 37.45, 37.28, 36.79, 36.56, 29.68, 27.37, 27.00, 26.11, 25.95, 25.04, 14.94 (CH.sub.3), 14.48 (CH.sub.3) ppm.

(133) FIG. 5 is a .sup.1H NMR spectrum (300 MHz, CDCl.sub.3, 298 K) of 4-bromo-N-(2-methyloctyl)aniline. FIG. 6 is a .sup.13C NMR spectrum (100 MHz, CDCl.sub.3, 298 K) of 4-bromo-N-(2-methyloctyl)aniline.

4-bromo-N-(cyclooctylmethyl)aniline

(134) ##STR00038##

(135) 4-bromo-N-methylaniline (93 mg, 0.5 mmol), cyclooctene (55 mg, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L5 (8 mg, 0.025 mmol). Reaction time: 6 h. Yield 95%. .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 7.25 (d, J.sub.H—H=8.8 Hz, m-C.sub.6H.sub.4), 6.47 (d, J.sub.H—H=8.8 Hz, o-C.sub.6H.sub.4), 3.75 (br s, 1H, NH), 2.90 (d, J.sub.H—H=6.8 Hz, NCH.sub.2), 1.86-1.24 (overlapping m, 13H, CH and CH.sub.2) ppm. .sup.13C NMR (CDCl.sub.3, 75 MHz, 298 K): δ 147.65 (i-C.sub.6H.sub.4), 131.95 (m-C.sub.6H.sub.4), 114.25 (o-C.sub.6H.sub.4), 108.40 (p-C.sub.6H.sub.4), 51.21 (NCH.sub.2), 37.33 (CH.sub.2), 30.67 (CH.sub.2), 27.13 (CH.sub.2), 26.41 (CH.sub.2), 25.58 (CH.sub.2) ppm.

(136) FIG. 7 is a .sup.1H NMR spectrum (300 MHz, CDCl3, 298 K) of 4-bromo-N-(cyclooctylmethyl)aniline. FIG. 8 is a .sup.13C NMR spectrum (100 MHz, CDCl3, 298 K) of 4-bromo-N-(cyclooctylmethyl)aniline.

4-chloro-N-(2-methyloctyl)aniline

(137) ##STR00039##

(138) 4-chloro-N-methylaniline (71 mg, 0.5 mmol), 1-octene (0.056 g, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L4 (8 mg, 0.025 mmol). Reaction time: 2 h. Yield 90%. .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 7.12 (d, J.sub.H—H=8.8 Hz, 2H, m-C.sub.6H.sub.5), 6.52 (d, J.sub.H—H=8.8 Hz, 2H, o-C.sub.6H.sub.5), 3.78 (br s, 1H, NH), 3.02 (dd, J.sub.H—H=5.9, 12.2 Hz, 1H, NC(H)H), 2.86 (dd, J.sub.H—H=7.2, 12.2 Hz, 1H, NC(H)H), 1.82-1.65 (m, 1H, 1.51-1.09 (m, 10H, CH.sub.2), 0.97 (d, J.sub.H—H=6.6 Hz, 3H, CHCH.sub.3), 0.91 (t, J.sub.H—H=6.8 Hz, 3H, CH.sub.2CH.sub.3) ppm. The chemical shifts for the title compound match those previously reported in the literature.

4-chloro-N-(cyclooctylmethyl)aniline

(139) ##STR00040##

(140) 4-chloro-N-methylaniline (71 mg, 0.5 mmol), cyclooctene (55 mg, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L5 (8 mg, 0.025 mmol). Reaction time: 6 h. Yield 93%. .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 7.10 (d, J.sub.H—H=8.8 Hz, m-C.sub.6H.sub.4), 6.51 (d, J.sub.H—H=8.8 Hz, o-C.sub.6H.sub.4), 3.71 (br s, 1H, NH), 2.90 (d, J.sub.H—H=6.8 Hz, NCH.sub.2), 1.87-1.21 (overlapping m, 13H, CH and CH.sub.2). ppm. .sup.13C NMR (CDCl.sub.3, 75 MHz, 298 K): δ 147.29 (i-C.sub.6H.sub.4), 129.10 (m-C.sub.6H.sub.4), 121.41 (p-C.sub.6H.sub.4), 113.73 (o-C.sub.6H.sub.4), 51.32 (NCH.sub.2), 37.38 (CH.sub.2), 30.70 (CH.sub.2), 27.14 (CH.sub.2), 26.43 (CH.sub.2), 25.59 (CH.sub.2) ppm.

(141) FIG. 9 is a .sup.1H NMR spectrum (300 MHz, CDCl3, 298 K) of 4-chloro-N-(cyclooctylmethyl)aniline. FIG. 10 is a .sup.13C NMR spectrum (100 MHz, CDCl.sub.3, 298 K) of 4-chloro-N-(cyclooctylmethyl)aniline.

4-fluoro-N-(2-methyloctyl)aniline

(142) ##STR00041##

(143) 4-fluoro-N-methylaniline (63 mg, 0.5 mmol), 1-octene (0.056 g, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L4 (8 mg, 0.025 mmol). Reaction time: 2 h. Yield 88%. .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 6.89 (t, J.sub.H—H=8.8 Hz, 2H, m-C.sub.6H.sub.5), 6.59-6.50 (m, 2H, o-C.sub.6H.sub.5), 3.57 (br s, 1H, NH), 3.02 (dd, J.sub.H—H=5.9, 12.1 Hz, 1H, NC(H)H), 2.85 (dd, J.sub.H—H=7.2, 12.0 Hz, 1H, NC(H)H), 1.82-1.65 (m, 1H, 1.51-1.11 (m, 10H, CH.sub.2), 0.98 (d, J.sub.H—H=6.7 Hz, 3H, CHCH.sub.3), 0.91 (t, JH—H=6.9 Hz, 3H, CH.sub.2CH.sub.3) ppm.

N-(cyclooctylmethyl)-4-fluoroaniline

(144) ##STR00042##

(145) 4-fluoro-N-methylaniline (63 mg, 0.5 mmol), cyclooctene (55 mg, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L5 (8 mg, 0.025 mmol). Reaction time: 6 h. Yield 88%. .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 6.89 (t, J.sub.H—H=8.7 Hz, 2H, m-C.sub.6H.sub.4), 6.57-6.49 (m, 2H, o-C.sub.6H.sub.4), 3.58 (br s, 1H, NH), 2.90 (d, J.sub.H—H=6.7 Hz, 2H, NCH.sub.2), 1.88-1.22 (overlapping m, 13H, CH and CH.sub.2) ppm. .sup.13C NMR (CDCl.sub.3, 100 MHz, 298 K): δ 155.68 (d, J.sub.C—F=234.2 Hz, p-C.sub.6H.sub.4), 145.05 (i-C.sub.6H.sub.4), 115.66 (d, J.sub.C—F=22.2 Hz, m-C.sub.6H.sub.4), 113.49 (d, J.sub.C—F=7.3 Hz, o-C.sub.6H.sub.4), 51.99 (NCH.sub.2), 37.41 (CH.sub.2), 30.72 (CH.sub.2), 27.15 (CH.sub.2), 26.43 (CH.sub.2), 25.60 (CH.sub.2) ppm. .sup.19F NMR (CDCl.sub.3, 282.4 MHz, 298 K): δ −129.00 (tt, J.sub.H—F=4.5 Hz, 1F, C.sub.6H.sub.4F) ppm.

(146) FIG. 11 is a .sup.1H NMR spectrum (300 MHz, CDCl3, 298 K) of N-(cyclooctylmethyl)-4-fluoroaniline. FIG. 12 is a .sup.13C NMR spectrum (75 MHz, CDCl3, 298 K) of N-(cyclooctylmethyl)-4-fluoroaniline

N-(2-methyloctyl)-4-(trifluoromethoxy)aniline

(147) ##STR00043##

(148) N-methyl-4-(trifluoromethoxy)aniline (96 mg, 0.5 mmol), 1-octene (0.056 g, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L4 (8 mg, 0.025 mmol). Reaction time: 3 h. Yield 92%. .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 7.03 (d, J.sub.H—H=8.2 Hz, 2H, m-C.sub.6H.sub.4), 6.59-6.50 (m, 2H, o-C.sub.6H.sub.4), 3.80 (br s, 1H, NH), 3.03 (dd, J.sub.H—H=5.9, 12.2 Hz, 1H, NC(H)H), 2.85 (dd, J.sub.H—H=7.3, 12.2 Hz, 1H, NC(H)H), 1.82-1.64 (m, 1H, 1.51-1.09 (m, 10H, CH.sub.2), 0.97 (d, J.sub.H—H=6.7 Hz, 3H, CHCH.sub.3), 0.90 (t, J.sub.H—H=6.9 Hz, 3H, CH.sub.2CH.sub.3) ppm. .sup.13C NMR (CDCl.sub.3, 300 MHz, 298 K): δ 147.51 (i-C.sub.6H.sub.5), 122.53 (C.sub.6H.sub.5), 112.89 (C.sub.6H.sub.5), 50.67 (NCH.sub.2), 34.90, 33.02, 32.00, 29.73, 27.07, 22.81, 18.17 (CH.sub.3), 14.23 (CH.sub.3) ppm. .sup.19F NMR (CDCl.sub.3, 282.4 MHz, 298 K): δ −58.81 (s, 3F, CF.sub.3) ppm.

(149) FIG. 13 is a .sup.1H NMR spectrum (300 MHz, CDCl3, 298 K) of N-(2-methyloctyl)-4-(trifluoromethoxy)aniline. FIG. 14 is a .sup.13C NMR spectrum (75 MHz, CDCl3, 298 K) of N-(2-methyloctyl)-4-(trifluoromethoxy)aniline.

N-(cyclooctylmethyl)-4-(trifluoromethoxy)aniline

(150) ##STR00044##

(151) N-methyl-4-(trifluoromethoxy)aniline (96 mg, 0.5 mmol), cyclooctene (55 mg, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L5 (8 mg, 0.025 mmol). Reaction time: 6 h. Yield 85%. .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 7.03 (d, J.sub.H—H=9.0 Hz, 2H, m-C.sub.6H.sub.4), 6.59-6.50 (m, 2H, o-C.sub.6H.sub.4), 3.77 (br s, 1H, NH), 0.2.92 (d, J.sub.H—H=6.5 Hz, 1H, NCH.sub.2), 1.89-1.21 (overlapping m, 13H, CH and CH.sub.2) ppm. .sup.13C NMR (CDCl.sub.3, 75 MHz, 298 K): δ 147.55 (i-C.sub.6H.sub.4), 122.51 (C.sub.6H.sub.4), 112.81 (C.sub.6H.sub.4), 51.43 (NCH.sub.2), 37.48, 30.73, 27.17, 26.44, 25.61 ppm. .sup.19F NMR (CDCl.sub.3, 282.4 MHz, 298 K): δ −58.79 (s, 3F, CF.sub.3) ppm.

(152) FIG. 15 is a .sup.1H NMR spectrum (300 MHz, CDCl3, 298 K) of N-(cyclooctylmethyl)-4-(trifluoromethoxy)aniline. FIG. 16 is a .sup.13C NMR spectrum (75 MHz, CDCl3, 298 K) of N-(cyclooctylmethyl)-4-(trifluoromethoxy)aniline.

N-(2-methyloctyl)benzo[d][1,3]dioxol-5-amine

(153) ##STR00045##

(154) N-methylbenzo[d][1,3]dioxol-5-amine (76 mg, 0.5 mmol), 1-octene (0.056 g, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L4 (8 mg, 0.025 mmol). Reaction time: 2 h. Yield 85%. .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 6.66 (d, J.sub.H—H=8.3 Hz, 2H, m-C.sub.6H.sub.3), 6.25 (d, J.sub.H—H=8.3 Hz, 1H, o-C.sub.6H.sub.3), 6.04 (dd, J.sub.H—H=2.3, 8.3 Hz, 1H, o-C.sub.6H.sub.3), 5.85 (s, 2H, OCH.sub.2), 3.48 (br s, 1H, NH), 2.99 (dd, J.sub.H—H=5.9, 12.0 Hz, 1H, NC(H)H), 2.84 (dd, J.sub.H—H=5.0, 12.2 Hz, 1H, NC(H)H), 1.81-1.62 (m, 1H, 1.50-1.08 (m, 10H, CH.sub.2), 0.97 (d, J.sub.H—H=6.7 Hz, 3H, CHCH.sub.3), 0.91 (t, J.sub.H—H=7.1 Hz, 3H, CH.sub.2CH.sub.3) ppm. .sup.13C NMR (CDCl.sub.3, 75 MHz, 298 K): δ 148.46 (i-C.sub.6H.sub.3), 144.64 (m-C.sub.6H.sub.3), 139.40 (p-C.sub.6H.sub.3), 108.75 (m-C.sub.6H.sub.3), 104.34 (OCH.sub.2), 100.62 (o-C.sub.6H.sub.3), 95.90 (o-C.sub.6H.sub.3), 51.54, 34.94, 33.03, 32.00, 29.74, 27.06, 22.80, 18.20 (CH.sub.3), 14.23 (CH.sub.3) ppm.

(155) FIG. 17 is a .sup.1H NMR spectrum (300 MHz, CDCl3, 298 K) of N-(2-methyloctyl)benzo[d][1,3]dioxol-5-amine. FIG. 18 is a .sup.13C NMR spectrum (75 MHz, CDCl3, 298 K) of N-(2-methyloctypenzo[d][1,3]dioxol-5-amine.

N-(4-((tert-butyldimethylsilyl)oxy)-2-methylbutyl)aniline

(156) ##STR00046##

(157) N-methylaniline (54 mg, 0.5 mmol), (but-3-en-1-yloxy)(tert-butyl)dimethylsilane (93 mg, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L4 (8 mg, 0.025 mmol). Reaction time: 2 h. Yield 75%. .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 7.20 (t, .sup.3J.sub.H—H=7.8, 2H, m-C.sub.6H.sub.4), 6.70 (td, .sup.3J.sub.H—H=0.9, 7.3, 1H, p-C.sub.6H.sub.4), 6.63 (d, .sup.3J.sub.H—H=8.5, 2H, o-C.sub.6H.sub.4), 3.85 (br s, 1H, NH), 3.83-3.64 (m, 2H, OCH.sub.2), 3.10 (dd, J.sub.H—H=6.3, 12.2 Hz, 1H, NC(H)H), 2.97 (dd, J.sub.H—H=6.9, 12.2 Hz, 1H, NC(H)H), 1.97 (oct, J.sub.H—H=6.7 Hz, 1H, OCH.sub.2C(H)H), 1.76-1.61 (m, 1H, CHCH.sub.3), 1.53-1.39 (m, 1H, OCH.sub.2C(H)H), 0.95 (d, J.sub.H—H=1.3 Hz, 9H, SiC(CH.sub.3).sub.3), 0.10 (d, J.sub.H—H=1.1 Hz, 6H, SiCH.sub.3) ppm. .sup.13C NMR (CDCl.sub.3, 75 MHz, 298 K): δ 148.71 (i-C.sub.6H.sub.5), 129.33 (m-C.sub.6H.sub.5), 117.00 (p-C.sub.6H.sub.5), 112.74 (o-C.sub.6H.sub.5), 77.16 (OCH.sub.2), 61.20 (NCH.sub.2), 50.43 (OCH.sub.2CH.sub.2), 37.94, 29.98, 26.10 (SiC(CH.sub.3).sub.3), 18.44 (CHCH.sub.3), −5.18 (SiCH.sub.3) ppm.

(158) FIG. 19: .sup.1H NMR spectrum (300 MHz, CDCl3, 298 K) of 4-((tert-butyldimethylsilyl)oxy)-2-methylbutyl)aniline. FIG. 20 is a .sup.13C NMR spectrum (75 MHz, CDCl3, 298 K) of 4-((tert-butyldimethylsilyl)oxy)-2-methylbutyl)aniline.

N-(2-cyclohexylpropyl)aniline

(159) ##STR00047##

(160) N-methylaniline (54 mg, 0.5 mmol), vinylcyclohexane (55 mg, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L4 (8 mg, 0.025 mmol). Reaction time: 2 h. Yield 86%. .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 7.25-7.17 (m, 2H, m-C.sub.6H.sub.4), 6.79-6.69 (m, 1H, p-C.sub.6H.sub.4), 6.69-6.63 (m, 2H, o-C.sub.6H.sub.4) 3.87 (br s, 1H, NH), 3.20 (dd, J.sub.H—H=5.5, 12.1 Hz, 1H, NC(H)H), 2.93 (dd, J.sub.H—H=7.9, 12.1 Hz, 1H, NC(H)H), 1.87-1.60 (overlapping m, 6H, CH and CH.sub.2.sup.Cy), 1.47-1.04 (m, 6H, CH.sub.2.sup.Cy), 0.99 (d, J.sub.H—H=6.9 Hz, 3H, CHCH.sub.3) ppm.

N-((1-methylcyclohexyl)methyl)aniline

(161) ##STR00048##

(162) N-methylaniline (54 mg, 0.5 mmol), vinylcyclohexane (48 mg, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L4 (8 mg, 0.025 mmol). Reaction time: 3 h. Yield 99%. .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 7.30-7.21 (m, 2H, m-C.sub.6H.sub.5), 6.82-6.66 (overlapping m, 3H, o-C.sub.6H.sub.5 and p-C.sub.6H.sub.5), 3.68 (br s, 1H, NH), 3.03 (s, 2H, NCH.sub.2), 1.69-1.33 (overlapping m, 10H, CH.sub.2.sup.Cy), 1.08 (s, 3H, CH.sub.3) ppm.

N-(2-(cyclohex-3-en-1-yl)propyl)aniline

(163) ##STR00049##

(164) N-methylaniline (54 mg, 0.5 mmol), vinylcyclohexane (55 mg, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L4 (8 mg, 0.025 mmol). Reaction time: 2 h. Yield 98%. .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 7.28-7.17 (m, 2H, m-C.sub.6H.sub.5), 6.75 (t, J.sub.H—H=6.8 Hz, 1H, m-C.sub.6H.sub.5), 6.67 (d, J.sub.H—H=7.8 Hz, 1H, o-C.sub.6H.sub.5), 5.75 (s, 2H, CH═CH.sub.2), 3.89 (br s, 1H, NH), 3.30-3.18 (m, 1H, NC(H)H), 3.05-2.92 (m, 1H, NC(H)H), 2.25-1.24 (overlapping m, 8H, CHCH.sub.3, CH.sub.2CH, and CH.sub.2), 1.07-0.98 (m, 3H, CH.sub.3) ppm. The chemical shifts for the title compound match those reported in the literature.

N-(2-methyl-4-phenylbutyl)aniline

(165) ##STR00050##

(166) N-methylaniline (54 mg, 0.5 mmol), 4-phenyl-1-butene (66 mg, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L4 (8 mg, 0.025 mmol). Reaction time: 3 h. Yield 87%. .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 7.38-7.28 (m, 2H, m-C.sub.6H.sub.5), 7.27-7.15 (overlapping m, 5H, m-NC.sub.6H.sub.5, o-C.sub.6H.sub.5, and p-C.sub.6H.sub.5), 6.72 (t, J.sub.H—H=7.1 Hz, 1H, p-NC.sub.6H.sub.5), 6.62 (d, J.sub.H—H=7.9 Hz, 2H, o-NC.sub.6H.sub.5), 3.69 (br s, 1H, NH), 3.13 (dd, J.sub.H—H=5.8, 12.3 Hz, 1H, NC(H)H), 2.97 (dd, J.sub.H—H=6.9, 12.3 Hz, 1H, NC(H)H), 2.84-2.57 (m, 2H, C.sub.6H.sub.5CH.sub.2), 1.92-1.75 (m, 2H, C.sub.6H.sub.5CH.sub.2CH.sub.2), 1.64-1.47 (m, 1H, CHCH.sub.3), 1.08 (d, J.sub.H—H=6.6 Hz, 2H, CHCH.sub.3) ppm. The chemical shifts for the title compound match those reported in the literature.

N-(2-(4-chlorophenyl)propyl)aniline

(167) ##STR00051##

(168) N-methylaniline (54 mg, 0.5 mmol), 4-chlorostyrene (70 g, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L4 (8 mg, 0.025 mmol). Reaction time: 2 h. Yield 98%. .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 7.31 (d, J.sub.H—H=8.4 Hz, 2H, m-C.sub.6H.sub.4C.sub.1), 7.23-7.14 (overlapping m, 4H, m-C.sub.6H.sub.4C.sub.1 and o-C.sub.6H.sub.5), 6.72 (t, J.sub.H—H=7.2 Hz, 1H, p-C.sub.6H.sub.5), 6.59 (d, J.sub.H—H=8.5 Hz, 2H, o-C.sub.6H.sub.5), 3.59 (br s, 1H, NH), 3.35 (dd, J.sub.H—H=6.1, 12.5 Hz, 1H, NC(H)H), 3.22 (dd, J.sub.H—H=8.2, 12.4 Hz, 1H, NC(H)H), 3.13-2.99 (m, 1H, CHCH.sub.3), 1.33 (d, J.sub.H—H=6.9 Hz, 3H, CHCH.sub.3) ppm.

N-(2-(2-bromophenyl)propyl)aniline (A) and N-(3-(2-bromophenyl)propyl)aniline (B)

(169) ##STR00052##

(170) N-methylaniline (54 mg, 0.5 mmol), 2-bromostyrene (92 mg, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L4 (8 mg, 0.025 mmol). Reaction time: 2 h. Yield 65%. .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): Product is a combination of linear and branched HAA products (˜9:1), additional spectra are required for full peak assignments.

(171) FIG. 21 is a .sup.1H NMR spectrum (300 MHz, CDCl.sub.3, 298 K) of a mixture between N-(2-(2-bromophenyl)propyl)aniline and N-(3-(2-bromophenyl)propyl)aniline.

N-(2-methyl-3-phenylpropyl)aniline (A) and N-(2-phenylbutyl)aniline (B)

(172) ##STR00053##

(173) N-methylaniline (54 mg, 0.5 mmol), cis/trans-β-methylstyrene (60 mg, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L5 (8 mg, 0.025 mmol). Reaction time: 48 h. Yield 78%. .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 7.42-7.12 (overlapping m, 14H, m-C.sub.6H.sub.5.sup.A, m-NC.sub.6H.sub.5.sup.A, o,p-C.sub.6H.sub.5.sup.A, o,m,p-C.sub.6H.sub.5.sup.B, and m-NC.sub.6H.sub.5.sup.B), 6.79-6.52 (overlapping m, 6H, p-NC.sub.6H.sub.5.sup.A, o-NC.sub.6H.sub.5.sup.A, p-NC.sub.6H.sub.5.sup.B, and o-NC.sub.6H.sub.5.sup.B), 3.69 (br s, 1H, NH.sup.A), 3.60-3.38 (overlapping m, 2H, NH.sup.B and NC(H)H.sup.B), 3.30-3.19 (m, 1H, NC(H)H.sup.B), 3.13 (dd, J.sub.H—H=6.0, 12.4 Hz, 1H, NC(H)H.sup.A), 2.98 (dd, J.sub.H—H=6.9, 12.3 Hz, 1H, NC(H)H.sup.A), 2.87-2.75 (m, 1H, C.sub.6H.sub.5CH.sup.B), 2.79 (dd, J.sub.H—H=6.3, 13.4 Hz, 1H, C.sub.6H.sub.5C(H)H.sup.A), 2.53 (dd, J.sub.H—H=6.3, 13.4 Hz, 1H, C.sub.6H.sub.5C(H)H.sup.A), 2.18-2.03 (m, 1H, CHCH.sub.3.sup.A), 1.92-1.77 (m, 1H, C(H)HCH.sub.3.sup.B), 1.77-1.60 (m, 1H, C(H)HCH.sub.3.sup.B) 1.01 (d, J.sub.H—H=6.7 Hz, CHCH.sub.3.sup.A) ppm.

N-(cyclohexylmethyl)aniline

(174) ##STR00054##

(175) N-methylaniline (54 mg, 0.5 mmol), cyclohexene (41 mg, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L5 (8 mg, 0.025 mmol). Reaction time: 20 h. Yield 70%. .sup.1 H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 7.23-7.11 (m, 1H, m-C.sub.6H.sub.5), 6.68 (t, J.sub.H—H=7.2 Hz, 1H, p-C.sub.6H.sub.5), 6.60 (d, K.sub.H—H=8.9 Hz, 2H, o-C.sub.6H.sub.5), 3.70 (br s, 1H, NH), 2.96 (d, J.sub.H—H=6.7 Hz, NCH.sub.2), 1.93-1.67 (m, 5H, CH.sub.2), 1.68-1.52 (m, 1H, CH), 1.39-1.21 (m, 3H, CH.sub.2), 1.11-0.93 (m, 1H, CH.sub.2) ppm. The chemical shifts for the title compound match those previously reported in the literature..sup.k,l

N-(cyclopentylmethyl)aniline

(176) ##STR00055##

(177) N-methylaniline (54 mg, 0.5 mmol), cyclopentene (34 mg, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L5 (8 mg, 0.025 mmol). Reaction time: 20 h. Yield 74%. .sup.1H NMR (CDCl.sub.3, 300 MHz, 298 K): δ 7.21 (t, J.sub.H—H=7.5 Hz, 2H, m-C.sub.6H.sub.5), 6.72 (t, J.sub.H—H=7.3 Hz, 1H, p-C.sub.6H.sub.5), 6.65 (d, J.sub.H—H=7.7 Hz, 2H, o-C.sub.6H.sub.5), 3.69 (br s, 1H, NH), 3.06 (d, J.sub.H—H=7.3 Hz, 2H, NCH.sub.2), 2.19 (hept, J.sub.H—H=7.6 Hz, 1H, NCH.sub.2CH), 1.94-1.80 (m, 2H, CH.sub.2), 1.77-1.52 (m, 4H, CH.sub.2), 1.40-1.23 (m, 2H, CH.sub.2) ppm.

N-(cycloheptylmethyl)aniline

(178) ##STR00056##

(179) N-methylaniline (54 mg, 0.5 mmol), cycloheptene (49 mg, 0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (13 mg, 0.025 mmol), L5 (8 mg, 0.025 mmol). Reaction time: 6 h. Yield 88%. .sup.1H NMR (400 MHz, CDCl.sub.3): δ 7.17 (t, J=7.4 Hz, 2H), 6.70 (t, J=7.2 Hz, 1H), 6.62 (d, J=8.0 Hz, 2H), 3.76 (br s, 1H), 2.97 (d, J=6.3 Hz, 2H), 1.90-1.40 (m, 11H), 1.35-1.20 (m, 2H).

EXAMPLES

(180) Various alternative embodiments and examples are described herein. These embodiments and examples are illustrative and should not be construed as limiting the scope of the invention. In particular, while tantalum was used as the representative group 5 metal for these studies, the skilled person will expect other group 5 metals, and especially niobium, to perform similarly.

Example 1: Group 5 Metal-Based Precursors as Catalysts

(181) In order to identify potentially promising group 5 metal/ligand salt combinations, the most common Ta precursors were screened in the absence of any ligand salt (Table 1). For this step, the standard benchmark reaction between N-methylaniline and 1-octene was chosen. It has previously been demonstrated that TaMe.sub.3Cl.sub.2 can catalyse this reaction, reaching a conversion of 91%, after 30 hours at 110° C. using a 10 mol % catalyst loading, but full conversion could never be achieved due to catalyst decay. Hence, optimization of the benchmark reaction was started by reducing the reaction time from 24 h to only 1 h. Under these conditions TaMe.sub.3Cl.sub.2 could afford a 28% conversion. Further catalytic screening confirmed that Ta-alkyl precursors can competently catalyse the addition of N-methylaniline to 1-octene, with Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 showing the most promising activity, achieving 39% conversion in only 1 h, when stoichiometric amounts of substrates were used. On the other hand, complexes bearing a Ta—NMe.sub.2 moiety were far less reactive, at best showing a 15% conversion after 24 hours of reaction. These data illustrated the promising catalytic activity of Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2. For this reason, Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 was chosen as the tantalum precursor for all subsequent catalytic experiments.

(182) TABLE-US-00001 TABLE 1 Screening of Ta precursors for intermolecular hydroaminoalkylation reactions..sup.a Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 1 h, 39% Ta(CH.sub.2CMe.sub.3).sub.3Cl.sub.2 25 h, 15% TaMe.sub.3Cl.sub.2 1 h, 28% Ta(NMe.sub.2).sub.5 24 h, n.r. [Ta(NMe.sub.2).sub.3Cl.sub.2].sub.2 1 h, n.r. 24 h, 15% .sup.aReaction conditions: amine (0.5 mmol), 1-octene (0.5 mmol), [Ta] precatalyst (0.025 mmol), d.sub.8 toluene (0.6 mL). Conversion determined by .sup.1H NMR spectroscopy. n.r. = no reaction.

Example 2: Ligand Salt Screening Using In-Situ Experiments

(183) Further catalytic experiments were performed by generating in situ the catalytic species by reacting Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 with a variety N,O-chelate type ligand salts.

(184) This study was extended to internal alkenes, adding the more challenging cyclohexene to the pool of substrates. In an effort to perform the catalytic screening under milder conditions, the reaction temperature for reactions using cyclohexene as a substrate were lowered from 145° C. to 130° C. For this step, attention was focussed on amidate (Table 2, L1), phosphoramidate (Table 2, L2), and pyridonate (Table 2, L3) sodium salts. In addition, a variety of ureate type ligand salts were also investigated. The latter type of ligands have previously been studied with group 4 metals for hydroamination and alkyne dimerization catalysis. Catalytic screening of in situ mixtures containing L1 and L2 resulted in no or poor conversion, regardless of the alkene substrate or the chosen reaction time. This behaviour is somewhat surprising considering that in the case of 1-octene, the related amidate-Ta(NMe.sub.2).sub.4 complex gave a 96% conversion of the addition product after 63 h of reaction time. Moreover, the in situ mixture between the ligand salt L2 and TaMe.sub.3Cl.sub.2 afforded 52% conversion after 20 h, at room temperature. On the other hand, using the less sterically encumbered pyridonate ligand salt L3 proved to be more successful as 31% and 33% conversions were observed for terminal and internal alkene substrates, respectively.

(185) TABLE-US-00002 TABLE 2 Screening of ligand salts in hydroaminoalkylation reactions..sup.a 0 Ligand Salt Alkene L1  1 h, n.r. 20 h, n.r. L2  1 h, n.r. 20 h, n.r. L3  1 h, 31% 20 h, 33% L4  1 h, 55% 24 h, 58%.sup.d L5  1 h, 37% 20 h, 34% L6  1 h, 83% 20 h, 19% L7  1 h, 12% 20 h, 83% 0 L8  1 h, 5% 20 h, 6% L9  1 h, 48% 20 h, 45% L10 1 h, 45% n/a L11 1 h, traces n/a L12 1 h, 93% n/a L13 1 h, 92% n/a .sup.aReaction conditions: amine (0.5 mmol), alkene (0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (0.025 mmol), ligand salt (0.025 mmol), d.sub.8-toluene (0.5 g). Conversion was determined by .sup.1H NMR spectroscopy. n.r. = no reaction. All reactions with 1-octene were performed at 110° C., while those with cyclohexene were performed at 130° C.

(186) Next, ureate salts were tested. In situ catalyst system with L6 was excellent, affording 83% conversion in only 1 h for the reaction between 1-octene and N-methylaniline with a TOF of more than 16 h.sup.−1. However, when the more challenging cyclohexene substrate was evaluated, only a modest 19% conversion was observed after 20 h. Remarkably, the mixed aryl/alkyl-substituted ureate ligand L7 resulted in a reversed trend; this system provided higher conversion of the internal alkene substrate (20 h, 83%), but was less effective for the terminal alkene substrate (1 h, 12%). These results are surprising considering that the only change is the N-Ph group of L6 to the N-iPr moiety in L7. Exchanging the remaining Ph group of L7 with an iPr group (L8) did not improve the catalytic system and poor conversions were obtained for both alkenes. Without wishing to be bound by an particular theory, the inventors propose that that the known hemilability of N,O-chelating ligands coupled with the variable coordination modes of ureate ligands results in a flexible coordination environment about the reactive metal center, thereby promoting reactivity.

(187) Table 3 provides additional data with respect to the effect of various ureate ligand salts on the addition of N-methylaniline to 1-octene.

(188) TABLE-US-00003 TABLE 3 Screening of ligand salts in hydroaminoalkylation reactions in which N- methylaniline is added to 1-octene. Temperature Time Conversion Ligand (° C.) (h) (%) 110 1 55 110 2 95 0 110 1 23 110 1 5 110 1 37 110 1 48 110 1 45 110 1 0 110 1 99 110 1 40 110 1 20 110 1 30 0 110 24 100 110 1 31 110 0.25 67 110 0.5 87 100 1 93 110 0.5 36

(189) Table 4 provides additional data with respect to the effect of various ureate ligand salts on the addition of N-methylaniline to cyclohexene.

(190) TABLE-US-00004 TABLE 4 Screening of ligand salts in hydroaminoalkylation reactions in which N- methylaniline is reacted with cyclohexene. Temperature Time Conversion Ligand (° C.) (h) (%) 145 24 58 130 20 35 00 130 20 83 01 145 20  6 02 145 20 34 03 130 20 45 04 130 20  0 05 130 20  0 06 150 20 82 07 130 20 20 08 130 20 70 09 130 20 42

Example 3: Amine Substrate Scope

(191) The study referred to in Tables 2 and 3 was extended by broadening the substrate scope in amine substrates. 1-Octene was kept as the preferred substrate for the terminal alkenes, whereas cyclohexene was swapped with cyclooctene, due to higher reactivity caused by the ring strain. As indicated in Table 5, catalytic mixtures including L6 were used to convert the terminal alkene, while ligand salt L7 was used exclusively for the internal alkene. Another objective was to purify the final products in an easy manner, by avoiding separation on the chromatographic column. For this reason, reaction times were adapted in order to favour full substrate conversion i.e. 2 h for 1-octene and 6 h for cyclooctene. As expected, the reaction between N-methylaniline and 1-octene (Table 5, Entry 1), resulted in a nearly complete conversion of the substrates with a TOF value of 9.5 h.sup.−1. Likewise, cyclooctene was fully converted within 6 hours, with an average of 3.3 turnovers per hour and an excellent 83% isolated yield (Table 5, Entry 1b). The pyridonate-Ta(NMe.sub.2).sub.3Cl.sub.2 complex can also catalyse this reaction, but in this case longer reaction times are needed (20 h), with a TOF value limited to 1 h.sup.−1 . Consistently with results reported in the literature, para-substituted N-methylanilines are well tolerated and good TOF values were recorded for both 1-octene (3-3.3 h.sup.−1) and cyclooctene (8.8-10 h .sup.−1) substrates. On the same note, the presence of halide substituents on the aromatic ring (Table 5, Entries 3-5) does not inhibit the reaction rates, opening the way for further functionalization via cross-coupling or nucleophilic aromatic substitution reactions. Perhaps more importantly, the potential pharmaceutically relevant aniline N-methyl-4-(trifluoromethoxy) aniline (Table 5, Entry 6) proved to be highly reactive under the specified catalytic conditions. Impressively, the presence of a dioxole unit was also well tolerated, as the corresponding addition product was easily obtained with an 85% yield.

(192) TABLE-US-00005 TABLE 5 Substrate scope in amine.sup.a 0 Isolated Entry Amine Alkene Yield (%)  1  2 a b 88 83  3  4 a b 77 70  5  6 a b 86 95  7  8 a b 90 93  9 10 a b 85 88 11 12 a b 92 85 13 a 85 .sup.aReaction conditions: amine (0.5 mmol), alkene (0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (0.025 mmol), ligand salt (0.025 mmol), d.sub.8-toluene (0.5 g). L4 was used for all terminal alkene substrates at 110° C. over 2 h and L5 was used for internal alkene substrates at 130° C. over 6 h.

(193) Table 6 provides additional data with respect to the addition of various amines to 1-octene in the presence of tantalum metal complexes.

(194) TABLE-US-00006 TABLE 6 Amine scope for hydroaminoalkylation reactions. Temperature Time Conversion Entry Amine Alkene (° C.) (h) (%) dr  1 0 150 20 100 16:1  2 150 20  65 >20:1   3 150 20 >20:1   4 150 20 100 10:1  5 150 20 100 >20:1   6 0 150 20 100  8:1  7 150 20 100 >20:1   8 n/a 150 20 100 n/a  9 150 20 100 1:1 regioisomers dr >20:1 10 150 20 100 >20:1  11 0 110 20  90 TBD 12 150 20 100 dr TBD 13 150 20  50 dr TBD 14 150  2 100 >20:1 Mostly bis- alkylated product obtained 15 150 20 100 1.79:1 (Branched:Linear regioisomers) dr 17:1 16 0 150 20 100 1.2:1 (Branched:Linear regioisomers) dr 19:1

Example 4: Alkene Substrate Scope

(195) Having tested the capability of the Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 containing catalytic system in broadening the substrate scope in amines, attention was switched to the alkene class of substituents (Table 7). In this respect, a variety of terminal, di-substituted alkenes and dienes were chosen as candidates. As before, L6 was used exclusively for terminal alkenes, while L7 was used in the case of the internal ones. Alkenes containing silyl protected OH moieties were easily reacted with N-methylaniline in less than 2 h to give the addition product in a 75% yield, and with an average of 8.6 turnovers per hour. Further catalytic screenings involved trimethyl(vinyl)silane, which upon reaction with N-methylaniline gives a 1:1 mixture (TOF=9.0 h.sup.−1) between the branched and linear product, perhaps as a consequence of the β-silicon effect. Even sterically hindered alkenes such as vinylcyclohexene and methylenecyclohexane are accommodated giving the corresponding addition products in excellent yields and TOF values of 9.1 h.sup.−1 and 6.6 h.sup.−1, respectively. Remarkably, 4-vinylcyclohex-1-ene was highly reactive under catalytic conditions (99% yield, TOF=10 h.sup.−1), when only the terminal C═C bond was selectively activated. This result is impressive as isolated dienes are particularly difficult to convert. Styrenes are no exception to the active class of substituents as 4-chlorostyrene and 2-bromo-styrene reacted quantitatively (TOF=10 and 10 h.sup.−1) with the amine, with no signs of polymerized product being observed. In the case of 2-bromo-styrene, the presence of the halide atom in the ortho position on the aryl ring notably does not sterically affect the outcome of the reaction. This observation is counterintuitive considering that under identical conditions, 2-methylstyrene was found to be completely inert.

(196) The substrate scope containing the more challenging internal alkenes was investigated next. First, α-methylstyrene required long reaction times (48 h) to ensure an almost complete conversion. α-methylstyrene can be fully converted in 24 h when the catalyst is supported by the smaller pyridonate type of ligands. The reactivity of cyclic internal alkenes was found to be directly proportional to the size of the ring, and therefore dependant on the ring strain. Hence, cyclooctene was found to be the most reactive (TOF=3.2 h.sup.−1), followed by cycloheptene (TOF=3 h.sup.−1), while cyclopentene (TOF=0.79 h.sup.−1) and cyclohexene (TOF=0.80 h.sup.−1) displayed a similar reactivity. Absence of the ring strain, as observed for the internal linear alkenes had a clear impact on the reactivity of these substrates. Indeed, compared to the cyclic alkenes, only moderate yields were obtained after 20 h i.e. 4-octene (55%), cis-3-hexene (55%), trans-3-hexene (32%).

(197) TABLE-US-00007 TABLE 7 Substrate scope in alkene..sup.a,b Turnover frequency values (h.sup.−1) are given in brackets. Ratio of branched:linear regioisomers are given in square brackets L6 L7 0 0 .sup.aReaction conditions: amine (0.5 mmol), alkene (0.5 mmol), Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 (0.025 mmol), ligand salt (0.025 mmol), d.sub.8-toluene (0.5 g). Conversion determined by .sup.1H NMR spectroscopy. All reactions with terminal alkene substrates we're performed with L6 at 110° C. Reactions with internal alkene substrates were performed with L7 at 130° C. .sup.bMajor isomer presented, yield refers to combined regioisomers.

(198) Table 8 provides additional data with respect to the addition of N-methyl butylamine to various alkenes.

(199) TABLE-US-00008 TABLE 8 Addition of various alkenes to N-methyl butylamine. Temperature Time Conversion Entry Alkene (° C.) (h) (%) 1 110 24 94 2 145 24 94 3 110 24 50 4 145 24  0 5 145  1  0 6 145 24 78

(200) Table 9 provides additional data with respect to the effect of various ureate ligand salts and metal complexes on the addition of piperidine to styrene.

(201) TABLE-US-00009 TABLE 9 Screening of ligand salts in hydroaminoalkylation reactions in which piperidine is reacted with styrene. 0 Temperature Time Percent Entry Ligand (° C.) (h) Conversion A:B dr 1 150 20 100 1.71:1 16:1 2 150 20 100 2:1 20:1 3 150 20 100 2.2:1 18:1 4 150 20 100 1.7:1 15:1 5 150 20 100 1.4:1 18:1

Example 5: Hydroamination Reaction Between Piperidine and 1-Octene

(202) Tables 10 and 11 provide data with respect to the effect of various ureate ligand salts and metal complexes on the addition of piperidine to 1-octene.

(203) TABLE-US-00010 TABLE 10 Hydroaminoalkylation data using cyclic ureate salts and Ta(CH.sub.2SiMe.sub.3).sub.3Cl.sub.2 for the reaction between piperidine and 1-octene. Ligand salt Time (h) Conversion (%) 144 100 144 100 Temperature Time Conversion Ligand (° C.) (h) (%) 0 150 6  0 150 6 100 150 6 100 150 6 100 150 6 100 150 6  37

Example 6. Effect of Temperature on Hydroaminoalkylation

(204) FIGS. 43 and 44 illustrate that the rate of the hydroaminoalkylation reaction for aryl and alkyl amines with 1-octene in the presence of metal complexes disclosed herein is temperature dependent and increases with temperature from 70° C. to 100° C.

Example 8. Effect of Catalyst Concentration on Hydroaminoalkylation

(205) FIG. 45 illustrates that the rate of the hydroaminoalkylation reaction for alkyl amines with 1-octene in the presence of metal complexes disclosed herein is concentration dependent and increases with concentration 2 mol % to 10 mol %.

Example 7. Effect of Halide Salts on Hydroaminoalkylation

(206) FIG. 46 illustrates that the rate of the hydroaminoalkylation reaction for aryl amines with 1-octene in the presence of metal complexes disclosed herein increases with the addition of halide salts. FIGS. 47 and 48 demonstrate that the rate of the hydroaminoalkylation reaction for aryl amines with 1-octene in the presence of metal complexes disclosed herein increases with the addition of KBr at temperatures from 70° C. to 100° C.

(207) Operation

(208) While specific embodiments of the invention have been described and illustrated, such embodiments should be considered illustrative of the invention only and not as limiting the invention as construed in accordance with the accompanying claims.