N-substituted pyridiniophosphines, processes for their preparation and their use

Abstract

The present invention deals with the synthesis and applications of new cationic compounds being useful as metal ligands. Specifically, N-alkyl/aryl substituted pyridiniophosphines are prepared and used as ligands for transition metals. The so-obtained metal complexes and their use as catalysts in chemical synthesis is also described. It also worth mentioning that N-alkyl/aryl pyridiniophosphines can be synthesized through a short, scalable and highly modular route.

Claims

1. N-substituted pyridiniophosphine of the general formula (I): ##STR00031## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are identical or different and each represent hydrogen, halogen, a linear, cyclic or branched C.sub.1-C.sub.20-alkyl, -alkenyl group or -alkynyl group or C.sub.5-C.sub.14-aryl or -heteroaryl group, which can have suitable substituents selected from halogen, O, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or heteroaryl, or at least one of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is bound to the pyridinio ring via O or NR, or at least two of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can form a linear or branched C.sub.4 to C.sub.12 alkyl ring, which can comprise at least one unsaturated bond and which can have suitable substituents selected from halogen, O, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or heteroaryl, or at least two of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can form a C.sub.5 to C.sub.14-aromatic or -heteroaromatic ring which can have suitable substituents selected from halogen, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or heteroaryl; R.sup.5 represents a linear, cyclic or branched C.sub.1-C.sub.20-alkyl group or C.sub.5-C.sub.14-aryl or -heteroaryl group, which can have suitable substituents selected from halogen, O, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or heteroaryl; R.sup.6 and R.sup.7 each represent a saturated or unsaturated, linear, branched or cyclic C.sub.1-C.sub.20-alkyl group or or C.sub.5-C.sub.14-aryl or -heteroaryl group, which can have suitable substituents selected from halogen, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or heteroaryl, or R.sup.6 and R.sup.7 can form a C.sub.4 to C.sub.20 ring which can comprise at least one unsaturated bond or an aromatic or heteroaromatic ring which can have suitable substituents selected from halogen, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or heteroaryl, R represents a C.sub.1-C.sub.20-alkyl group or C.sub.5-C.sub.14-aryl or -heteroaryl group which can have suitable substituents selected from halogen, O, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or heteroaryl, and X.sup. is an anion.

2. N-substituted pyridiniophosphine of the general formula (I) according to claim 1, wherein R.sup.1, R.sup.3 and R.sup.4 each represent hydrogen and R.sup.2 represents halogen, a linear, cyclic or branched C.sub.1-C.sub.20-alkyl, -alkenyl or -alkynyl group or C.sub.5-C.sub.14-aryl or -heteroaryl group, which can have suitable substituents selected from halogen, O, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or R.sup.2 is bound to the pyridinio ring via O or NR; and R.sup.5, R.sup.6, R.sup.7, R and X.sup. have the meaning as given in claim 1.

3. N-substituted pyridiniophosphine of the general formula (I) according to claim 1, wherein X.sup. is an anion selected from Cl.sup., Br.sup., I.sup., PF.sub.6.sup., SbF.sub.6.sup., BF.sub.4.sup., ClO.sub.4.sup., F.sub.3CCOO.sup., Tf.sub.2N.sup., (Tf=trifluoromethanesulfonyl), TfO.sup., tosyl, [B[3,5-(CF.sub.3).sub.2C.sub.6H.sub.3].sub.4].sup., [B(C.sub.6F.sub.5).sub.4].sup., and [Al(OC(CF.sub.3).sub.3).sub.4].sup..

4. A process for the preparation of N-substituted pyridiniophosphine with the general formula I: ##STR00032## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are identical or different and each represent hydrogen, halogen, a linear, cyclic or branched C.sub.1-C.sub.20-alkyl, -alkenyl group or -alkynyl group or C.sub.5-C.sub.14-aryl or -heteroaryl group, which can have suitable substituents selected from halogen, O, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or heteroaryl, or at least one of R.sup.2, R.sup.3 and R.sup.4 is bound to the pyridinio ring via O or NR, or at least two of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can form a linear or branched C.sub.4-C.sub.12-alkyl ring, which can comprise at least one unsaturated bond and which can have suitable substituents selected from halogen, O, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or heteroaryl, or at least two of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can form a C.sub.5-C.sub.14-aromatic or -heteroaromatic ring which can have suitable substituents selected from halogen, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or heteroaryl; R.sup.5 represents a linear, cyclic or branched C.sub.1-C.sub.20-alkyl group or C.sub.5-C.sub.14-aryl or -heteroaryl group, which can have suitable substituents selected from halogen, O, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or heteroaryl; R.sup.6 and R.sup.7 each represent a saturated or unsaturated, linear, branched or cyclic C.sub.1-C.sub.20-alkyl group or C.sub.5-C.sub.14-aryl or -heteroaryl group, which can have suitable substituents selected from halogen, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or heteroaryl, or R.sup.6 and R.sup.7 can form a C.sub.4 to C.sub.20 ring which can comprise at least one unsaturated bond or an aromatic or heteroaromatic ring which can have suitable substituents selected from halogen, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or heteroaryl; R represents a C.sub.1-C.sub.20-alkyl group or C.sub.5-C.sub.14-aryl or -heteroaryl group which can have suitable substituents selected from halogen, O, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or heteroaryl, and X.sup. is an anion, in which process a pyridinio-compound salt with the general formula II: ##STR00033## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and X.sup. are defined as above and Q represents a leaving group, is reacted with a phosphine of the general formula III:
HPR.sup.6R.sup.7(III) in which R.sup.6 and R7 are defined as above.

5. A metal complex comprising as a ligand a N-substituted pyridiniophosphine of the general formula (I) according to claim 1.

6. Metal complex of the general formula (IV) ##STR00034## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are identical or different and each represent hydrogen, halogen, a linear, cyclic or branched C.sub.1-C.sub.20-alkyl, -alkenyl group or -alkynyl group or C.sub.5-C.sub.14-aryl or -heteroaryl group, which can have suitable substituents selected from halogen, O, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or heteroaryl, or at least one of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is bound to the pyridinio ring via O or NR, or at least two of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can form a linear or branched C.sub.4-C.sub.12-alkyl ring, which can comprise at least one unsaturated bond and which can have suitable substituents selected from halogen, O, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or heteroaryl, or at least two of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can form a C.sub.5-C.sub.14-aromatic or -heteroaromatic ring which can have suitable substituents selected from halogen, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or heteroaryl; R.sup.5 represents a linear, cyclic or branched C.sub.1-C.sub.20-alkyl group or C.sub.5-C.sub.14-aryl or -heteroaryl group, which can have suitable substituents selected from halogen, O, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or heteroaryl; R.sup.6 and R.sup.7 each represent a saturated or unsaturated, linear, branched or cyclic C.sub.1-C.sub.20-alkyl group or C.sub.5-C.sub.14-aryl or -heteroaryl group, which can have suitable substituents selected from halogen, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or heteroaryl; or R.sup.6 and R.sup.7 can form a C.sub.4 to C.sub.20 ring which can comprise at least one unsaturated bond or an aromatic or heteroaromatic ring which can have suitable substituents selected from halogen, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or heteroaryl, R represents a C.sub.1-C.sub.20-alkyl group or C.sub.5-C.sub.14-aryl or -heteroaryl group which can have suitable substituents selected from halogen, O, OH, OR, NH.sub.2, NHR, NR.sub.2, aryl or heteroaryl, and X.sup. is an anion, M represents a metal atom, L represents a ligand which can be also cationic, neutral or anionic and can be the same or different if more than one L is coordinated to the metal, and m can be 1, 2 or 3, n can be 1, 2 or 3, o can be an integer from 1 to 5, and m, n and o are chosen, depending on the metal atom, to obtain a metal complex.

7. The metal complex as claimed in claim 6, wherein the ligand L can be chosen from halogen, CN, CO, alkenes, cycloalkenes and/or alkynes, arenes, nitriles, phosphines, amines, pyridines or carboxylates.

8. The metal complex as claimed in claim 6, wherein M is selected from Ag, Au, Ru, Rh, Pd, Os, Ir and Pt.

9. An organic synthesis process comprising conducting a chemical reaction in the presence of a catalyst, wherein the catalyst is the metal complex as claimed in claim 6.

10. N-substituted pyridiniophosphine of the general formula (I) according to claim 1, wherein heteroaryl is selected from among the groups 2- or 3-furyl, 2- or 3-thienyl, 1-, 2- or 3-pyrrolyl, 1-, 2-, 4- or 5-imidazolyl, 1-, 3-, 4- or 5-pyrazolyl, 2-, 4- or 5-oxazolyl, 3-, 4- or 5-isoxazolyl, 2-, 4- or 5-thiazolyl, 3-, 4- or 5-isothiazolyl, 2-, 3- or 4-pyridyl, 2-, 4-, 5- or 6-pyrimidinyl, 1,2,3-triazol-1-, -4- or -5-yl, 1,2,4-triazol-1-, -3- or -5-yl, 1- or 5-tetrazolyl, 1,2,3-oxadiazol-4- or -5-yl, 1,2,4-oxadiazol-3- or -5-yl, 1,3,4-thiadiazol-2- or -5-yl, 1,2,4-thiadiazol-3- or -5-yl, 1,2,3-thiadiazol-4- or -5-yl, 3- or 4-pyridazinyl, pyrazinyl, 1-, 2-, 3-, 4-, 5-, 6- or 7-indolyl, 4- or 5-isoindolyl, 1-, 2-, 4- or 5-benzimidazolyl, 1-, 3-, 4-, 5-, 6- or 7-benzopyrazolyl, 2-, 4-, 5-, 6- or 7-benzoxazolyl, 3-, 4-, 5-, 6- or 7-benzisoxazolyl, 2-, 4-, 5-, 6- or 7-benzothiazolyl, 2-, 4-, 5-, 6- or 7-benzisothiazolyl, 4-, 5-, 6- or 7-benz-2,1,3-oxadiazolyl, 2-, 3-, 4-, 5-, 6-, 7- or 8-quinolyl, 1-, 3-, 4-, 5-, 6-, 7- or 8-isoquinolyl, 3-, 4-, 5-, 6-, 7- or 8-cinnolinyl, 2-, 4-, 5-, 6-, 7- or 8-quinazolinyl, 5- or 6-quinoxalinyl, 2-, 3-, 5-, 6-, 7- or 8-2H-benzo-1,4-oxazinyl, 1,3-benzodioxol-5-yl, 1,4-benzodioxan-6-yl, 2,1,3-benzothiadiazol-4- or -5-yl or 2,1,3-benzoxadiazol-5-yl, each of which heteroaryl groups is optionally substituted as provided in claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is further illustrated by the attached Figures. These Figures show:

(2) FIG. 1: Structural features of pyridinium-substituted phosphines;

(3) FIG. 2: Crystal structure of compound 12. Hydrogen atoms and the BF.sub.4 anion were omitted for clarity; ellipsoids are set at 50% probability;

(4) FIG. 3: Ligand effect on the Pt-catalyzed hydroarylation of propargyl aryl ether 35 to chromene 36;

(5) FIG. 4: Ligand effect on the Pt-catalyzed cycloisomerization of enyne 37 to cyclobutene 38;

(6) FIG. 5: Ligand effect on the Au-catalyzed hydroarylation of alkyne 39 with arene 40; FIG. 6: Scheme 1: Synthesis of pyridinium-substituted phosphines;

(7) FIG. 7: Scheme 2: Synthesis of Rh complexes and crystal structure of 23. Hydrogen atoms and BF.sub.4 anions were omitted for clarity; ellipsoids are set at 50% probability; and

(8) FIG. 8: Scheme 3: Synthesis of Pt and Au complexes and crystal structure of 28 and 31.

(9) In more detail, the Figures and Schemes show:

(10) FIG. 1 illustrates structural features of the inventive pyridinium-substituted phosphines and their impact on the donor properties of the resulting ligand.

(11) FIG. 2 depicts the structure of 12 in the solid state. The P1-C1 distance (1.8551(7) ) is only slightly longer than the other two CP bonds (P1-C7, 1.8260(7) ; P1-C13, 1.8244(7) ) probably due to the increased steric hindrance of the N-methylpyridinium rest when compared with the two phenyl rings. In addition, the degree of pyramidalization at phosphorus (61.3%) is even slightly higher than that observed for PPh.sub.3 (56.7%). These parameters suggest retention of the nonbonding electron pair at the phosphorus atom.

(12) FIG. 3 shows the ligand effect on the Pt-catalyzed hydroarylation of propargyl aryl ether to chromene 36.

(13) Reagent and Conditions:

(14) a) 33 (0.05 M), Pt precatalysts 2 mol %, AgSbF.sub.6 2 mol %, (CH.sub.2).sub.2Cl.sub.2, 80 C. Conversions determined by gas chromatography.

(15) FIG. 4 shows the ligand effect on the Pt-catalyzed cycloisomerization of enyne 37 to cyclobutene 38.

(16) Reagent and Conditions:

(17) a) 37 (0.05 M), Pt precatalysts 2 mol %, AgSbF.sub.6 2 mol %, (CH.sub.2).sub.2Cl.sub.2, r.t. Conversions determined by gas chromatography.

(18) FIG. 5 shows the ligand effect on the Au-catalyzed hydroarylation of alkyne 39 with arene 40.

(19) Reagent and Conditions:

(20) a) 39 (0.05 M), 40 (4 equiv.; 0.2 M) Au precatalysts 5 mol %, AgX 5 mol %, (CH.sub.2).sub.2Cl.sub.2, 60 C. Conversions determined by gas chromatography.

(21) FIG. 6 (Scheme 1) illustrates the synthesis of pyridinium-substituted phosphines.

(22) Reagents and Conditions (Yields):

(23) a) MeOBF.sub.4 or EtOBF.sub.4, CH.sub.2Cl.sub.2, rt; 6 (91%); 8 (99%); 9 (99%); 10 (98%); 11 (89%); b) 5 (1.2 eq.), Iodobenzene (1 equiv.), CuBr (10 mol %), Cs.sub.2CO.sub.3 (2.1 eq), DMSO, 60 C., (95%); c) oxalyl chloride (3 equiv.), Cl(CH.sub.2).sub.2Cl, and then NaBF.sub.4 (4 equiv.), (71%); d) diaryl/alkylphosphine (2 equiv.), THF, 65 C.; 12 (70%), 1-3 days; 13 (80%); 14 (71%); (43%); 16 (60%); 17 (77%); 18 (89%); 19 (30%).

(24) FIG. 7 (Scheme 2) illustrates the synthesis of Rh complexes and crystal structure of 23. Hydrogen atoms and BF.sub.4 anions were omitted for clarity; ellipsoids are set at 50% probability.

(25) Reagent and Conditions (Yields):

(26) a) [RhCl(CO).sub.2].sub.2 (0.25 eq.), CH.sub.2Cl.sub.2, rt; 20 (99%); 21 (77%); 22 (57%); 23 (78%); 24 (74%).

(27) FIG. 8 (Scheme 3) illustrates the synthesis of Pt and Au complexes and crystal structure of 28 and 31. Hydrogen atoms, solvent molecules and BF.sub.4 anions were omitted for clarity; ellipsoids are set at 50% probability.

(28) Reagent and Conditions (Yields):

(29) a) K.sub.2PtCl.sub.4 (1.0 eq.), CH.sub.3CN, rt; 28 (80%); 29 (40%); b) (Me.sub.2S)AuCl (1.0 eq.), CH.sub.2Cl.sub.2, rt; 30 (97%); 31 (69%); 32 (98%); 33 (98%); 34 (38%).

(30) The invention is further illustrated in the following experimental part.

(31) General Procedures

(32) All reactions were carried out in flame-dried glassware under Argon. All the solvents were purified by distillation over the drying agents indicated and were transferred under Argon. CH.sub.2Cl.sub.2 (CaH.sub.2), hexane, toluene (Na/K). Flash chromatography: Merck silica gel 60 (230-400 mesh). IR: Nicolet FT-7199 spectrometer, wavenumbers in cm.sup.1. MS (EI): Finnigan MAT 8200 (70 eV), ESI-MS: Finnigan MAT 95, accurate mass determinations: Bruker APEX III FT-MS (7 T magnet). NMR: Spectra were recorded on a Bruker DPX 300 or AV 400 spectrometer in the solvents indicated; .sup.1H and .sup.13C chemical shifts () are given in ppm relative to TMS, coupling constants (J) in Hz. The solvent signals were used as references and the chemical shifts converted to the TMS scale. All commercially available compounds (Acros, Fluka, Lancaster, Alfa Aesar, Aldrich) were used as received unless stated otherwise. Compounds 7, 35 and 37 were prepared accordingly to the procedure described in the literature.

(33) General Procedure for the Alkylation of 2-Chloropyridines

(34) A solution of the corresponding 2-chloropyridine (1 equiv.) in DCM (0.05 M) was added to solid Me.sub.3OBF.sub.4 or Et.sub.3OBF.sub.4 (1 equiv.) and the suspension stirred overnight. Then, the solvent was filtered off and the remaining white solid washed twice with dichloromethane and dried in vacuum.

(35) ##STR00006##
Prepared from 2-chloropyridine (2.0 g, 17.6 mmol) and Me.sub.3OBF.sub.4 (2.6 g, 17.6 mmol) following the general procedure. After washing with DCM (220 ml), 6 was obtained as a white solid (3.47 g, 91%).

(36) .sup.1H NMR (300 MHz, CD.sub.3CN) =8.75 (d, J=6.2 Hz, 1H), 8.47 (td, J=8.2, 1.5 Hz, 1H), 8.12 (d, J=8.3 Hz, 1H), 7.94 (t, .sup.3J=6.8 Hz, 1H), 4.30 (s, 3H); .sup.13C NMR (75 MHz, CD.sub.3CN) =148.98, 148.96, 148.38, 131.00, 127.40, 48.62; IR (neat) {tilde over (v)}=712, 735, 778, 805, 1024, 1123, 1177, 1274, 1286, 1314, 1446, 1499, 1574, 1623, 3059, 3094, 3115, 3138 cm.sup.1 HRMS calcd. for C.sub.12H.sub.14BCl.sub.2F.sub.4N.sub.2: 343.056684. found: 343.056646.

(37) ##STR00007##
Prepared from 2-chloro-5-fluoropyridine (1.0 g, 7.6 mmol) and Me.sub.3OBF.sub.4 (1.12 g, 7.6 mmol) following the general procedure. After washing with DCM (220 ml), 8 was obtained as a white solid (1.75 g, 99%).

(38) .sup.1H NMR (300 MHz, CD.sub.3CN) =8.88 (t, J=3.1 Hz, 1H), 8.36 (ddd, J=9.4, 6.7, 2.9 Hz, 1H), 8.16 (dd, J=9.3, 4.9 Hz, 1H), 4.31 (s, 3H); .sup.13C NMR (75 MHz, CD.sub.3CN) =159.92 (d, J.sub.C-F=255.1 Hz), 145.62, 138.70 (d, J.sub.C-F=40.0 Hz), 136.23 (d, J.sub.C-F=19.8 Hz), 132.21 (d, J.sub.C-F=7.9 Hz), 49.46; .sup.19F NMR (282 MHz, CD.sub.3CN) =120.22, 151.77, 151.82; IR (neat) {tilde over (v)}=655, 698, 743, 767, 854, 901, 1022, 1126, 1165, 1282, 1392, 1439, 1509, 1593, 1641, 3084, 3104 cm.sup.1; HRMS calcd. for C.sub.12H.sub.12N.sub.2BCl.sub.2F.sub.6: 379.036928. found: 379.037035.

(39) ##STR00008##
Prepared from 2-chloro-5-(trifluoromethyl)pyridine (400 mg, 2.2 mmol) and Me.sub.3OBF.sub.4 (325 mg, 2.2 mmol) following the general procedure. After washing with DCM (22 ml), 9 was obtained as a white solid (620 mg, 99%).

(40) .sup.1H NMR (300 MHz, CD.sub.3CN) =9.23 (s, 1H), 8.75 (dd, J=8.7, 2.0 Hz, 1H), 8.34 (d, J=8.7 Hz, 1H), 4.39 (s, 3H); .sup.13C NMR (75 MHz, CD.sub.3CN) =153.30, 147.41 (m), 144.96 (q, J.sub.C-F=3.0 Hz), 132.13, 129.37 (q, J.sub.C-F=37.0 Hz), 122.32 (q, J.sub.C-F=272.7 Hz), 49.45; .sup.19F NMR (282 MHz, CD.sub.3CN) =63.45, 151.99, 152.04; IR (neat) {tilde over (v)}=663, 690, 722, 804, 861, 888, 916, 944, 998, 1025, 1125, 1192, 1268, 1331, 1435, 1479, 1590, 1639, 2296, 2342, 2383, 3055 cm.sup.1; HRMS calcd. for C.sub.7H.sub.6NClF.sub.3: 196.013540. found: 196.013563.

(41) ##STR00009##
Prepared from 2-chloro-5-methoxypyridine (965 mg, 6.72 mmol) and Me.sub.3OBF.sub.4 (994 mg, 6.72 mmol) in DCM (20 ml) following the general procedure. After washing with DCM (220 ml), 11 was obtained as a white solid (1.47 g, 89%).

(42) .sup.1H NMR (300 MHz, CD.sub.3CN) =8.47 (d, J=2.7 Hz, 1H), 8.10-7.93 (m, 2H), 4.27 (s, 3H), 4.00 (s, 3H); .sup.13C NMR (75 MHz, CD.sub.3CN) =158.33, 140.00, 136.02, 134.07, 130.94, 58.76, 48.98; .sup.19F NMR (282 MHz, CD.sub.3CN) =151.67, 151.72; IR (neat) {tilde over (v)}=697, 739, 847, 875, 936, 1013, 1037, 1099, 1159, 1177, 1197, 1271, 1308, 1391, 1425, 1445, 1469, 1513, 1590, 1622, 3101, 3156 cm.sup.1; HRMS calcd. for C.sub.14H.sub.18N.sub.2BCl.sub.2F.sub.4O.sub.2: 403.077864. found: 403.078070.

(43) ##STR00010##
Prepared from 2-chloro-5-(trifluoromethyl)pyridine (1 g, 5.5 mmol) and Et.sub.3OBF.sub.4 (1.05 g, 5.5 mmol) in DCM (20 ml) following the general procedure and purified by filtration and washing with DCM (210 ml) to afford 10 as a white solid (1.6 g, 5.4 mmol, 99%).

(44) .sup.1H NMR (300 MHz, CD.sub.3CN) =9.24 (d, J=0.7 Hz, 1H), 8.74 (dd, J=8.7, 2.1 Hz, 1H), 8.34 (d, J=8.7 Hz, 1H), 4.82 (q, J=7.3 Hz, 2H), 1.62 (t, J=7.3 Hz, 3H); .sup.13C NMR (75 MHz, CD.sub.3CN)=152.27, 146.25, 144.89 (q, J.sub.C-F=3.0 Hz), 132.79, 129.92 (q, J.sub.C-F=36.9 Hz), 122.21 (q, J.sub.C-F=273.7 Hz); .sup.19F NMR (282 MHz, CD.sub.3CN) =63.46, 151.88, 151.94; IR (neat) {tilde over (v)}=727, 740, 767, 809, 858, 939, 1023, 1056, 1095, 1110, 1146, 1183, 1193, 1233, 1299, 1328, 1395, 1413, 1453, 1473, 1509, 1586, 1639, 3089 cm.sup.1; HRMS calcd. for C.sub.8H.sub.8NClF.sub.3: 210.029185. found: 210.028857.

(45) General Procedure for the Preparation of Pyridiniophosphines

(46) To a solution of the corresponding 1-alkyl/aryl-2-chloropyridinium tetrafluoroborate (1 equiv.) in THF (2 ml) was added the desired secondary phosphine (2.5-3.0 equiv.) and the resulting suspension heated for 1 to 7 days. After cooling to rt, the solvents were evaporated and the crude reaction mixture washed with n-Pentan (22 ml), solved in DCM and washed with sat. NaBF.sub.4 aqueous solution. The organic phase was dried over NaSO.sub.4 and the solvent evaporated. If necessary, the resulting solid could be further purified by an additional wash with THF (1-2 ml).

(47) ##STR00011##
Prepared by heating a THF suspension of 6 (400 mg, 1.8 mmol) and diphenylphosphine (1.1 ml, 5.6 mmol) at 65 C. for 3 days. White solid (477 mg, 70%).

(48) .sup.1H NMR (300 MHz, CDCl.sub.3) =9.04 (d, J=5.7 Hz, 1H), 8.25 (td, J=7.9, 0.9 Hz, 1H), 8.03-7.95 (m, 1H), 7.57-7.43 (m, 6H), 7.39-7.27 (m, 5H), 4.30 (d, J=1.1 Hz, 3H); .sup.13C NMR (75 MHz, CDCl.sub.3) =161.02 (d, J.sub.C-P=33.4 Hz), 149.54, 144.04, 134.70 (d, J.sub.C-P=21.7 Hz), 132.63, 131.60, 130.20 (d, J.sub.C-P=8.4 Hz), 129.03 (d, J=6.7 Hz), 127.96, 47.64 (d, J.sub.C-P=21.0 Hz); .sup.31P NMR (121 MHz, CDCl.sub.3) =8.61; IR (neat) {tilde over (v)}=696, 724, 748, 798, 954, 1000, 1038, 1051, 1161, 1181, 1265, 1310, 1436, 1492, 1571, 1610, 3055, 3103, 3134 cm.sup.1; HRMS calcd. for C.sub.18H.sub.17NP: 278.109315. found: 278.109239.

(49) ##STR00012##
Prepared by heating a THF suspension of 6 (500 mg, 2.3 mmol) and dicyclohexylphosphine (0.75 ml, 5.8 mmol) at 65 C. for 3 days. White solid (699 mg, 80%).

(50) .sup.1H NMR (400 MHz, CDCl.sub.3) =9.11 (d, J=5.2 Hz, 1H), 8.48 (t, J=7.8 Hz, 1H), 8.05 (dd, J=14.3, 7.5 Hz, 2H), 4.59 (s, 3H), 2.11 (t, J=11.8 Hz, 2H), 1.91 (d, J=12.0 Hz, 2H), 1.81 (d, J=12.8 Hz, 2H), 1.69 (t, J=11.9 Hz, 4H), 1.51 (d, J=12.5 Hz, 2H), 1.41-1.01 (m, 10H); .sup.13C NMR (101 MHz, CDCl.sub.3) =160.33 (d, J.sub.C-P=42.5 Hz), 149.73, 143.58, 133.44 (d, J.sub.C-P=3.2 Hz), 128.24, 48.82 (d, J.sub.C-P=26.1 Hz), 34.36 (d, J.sub.C-P=15.1 Hz), 29.95 (d, J.sub.C-P=15.9 Hz), 29.44 (d, J.sub.C-P=8.6 Hz), 26.78 (d, J.sub.C-P=12.5 Hz), 26.65 (d, J.sub.C-P=8.8 Hz), 25.91; .sup.31P NMR (162 MHz, CDCl.sub.3) =3.52; IR (neat) {tilde over (v)}=728, 779, 851, 915, 1053, 1179, 1262, 1448, 1497, 1571, 1610, 2851, 2925 cm.sup.1; HRMS calcd. for C.sub.18H.sub.29NP: 290.203217. found: 290.203415.

(51) ##STR00013##
Prepared by heating a THF suspension of 7 (650 mg, 2.3 mmol) and diphenylphosphine (1.2 ml, 6.9 mmol) at 130 C. for 12 h in a wave oven. White solid (715 mg, 71%).

(52) .sup.1H NMR (300 MHz, CDCl.sub.3) =8.76 (d, J=5.1 Hz, 1H), 8.46 (td, J=8.0 Hz, 1.3, 1H), 8.06 (t, J=6.9 Hz, 1H), 7.66-7.50 (m, 4H), 7.50-7.37 (m, 6H), 7.32-7.21 (m, 6H); .sup.13C NMR (75 MHz, CD.sub.3CN) =149.53, 146.74, 135.83 (d, J.sub.C-P=22.5 Hz), 134.40, 132.53, 132.11, 131.40 (d, J.sub.C-P=8.2 Hz), 130.58 (d, J.sub.C-P=7.6 Hz), 128.25, 127.40 (d, J.sub.C-P=3.8 Hz); .sup.19F NMR (282 MHz, CDCl.sub.3) =151.82, 151.87; .sup.31P NMR (121 MHz, CDCN) =7.74; IR (neat) {tilde over (v)}=692, 699, 734, 748, 757, 786, 841, 863, 901, 931, 979, 997, 1011, 1035, 1047, 1079, 1163, 1178, 1254, 1288, 1315, 1438, 1455, 1475, 1492, 1563, 1589, 1607, 3070, 3117 cm.sup.1; HRMS calcd. for C.sub.23H.sub.19NP: 340.124626. found: 360.124961.

(53) ##STR00014##
Prepared by heating a THF suspension of 8 (500 mg, 2.14 mmol) and diphenylphosphine (0.92 ml, 5.35 mmol) at 65 C. for 3 days. White solid (351 mg, 43%).

(54) .sup.1H NMR (300 MHz, CD.sub.3CN) =8.94-8.82 (m, 1H), 8.18-8.07 (m, 1H), 7.58 (m, 6H), 7.42 (m, 5H), 4.23 (d, J=1.4 Hz, 3H); .sup.13C NMR (75 MHz, CDCN) =160.91 (d, J.sub.C-F=255.7 Hz), 139.81 (d, J.sub.C-P=38.2 Hz), 135.66 (d, J.sub.C-P=0.9 Hz), 135.62 (d, J.sub.C-P=21.9 Hz), 132.84 (d, J.sub.C-P=17.4 Hz), 132.43 (d, J.sub.C-P=0.6 Hz), 130.92 (d, J.sub.C-P=8.3 Hz), 130.28 (d, J.sub.C-P=6.7 Hz), 49.12 (d, J.sub.C-P=21.5 Hz); .sup.31P NMR (121 MHz, CDCl.sub.3) =9.34; IR (neat) {tilde over (v)}=699, 715, 738, 753, 760, 858, 895, 931, 958, 998, 1024, 1143, 1165, 1181, 1273, 1314, 1384, 1436, 1479, 1500, 1583, 1623 cm.sup.1; HRMS calcd. for C.sub.18H.sub.16NFP: 296.099965. found: 296.099889.

(55) ##STR00015##
Prepared by heating a THF suspension of 9 (500 mg, 1.8 mmol) and diphenylphosphine (0.62 ml, 4.4 mmol) at 65 C. for 1 day. White solid (451 mg, 60%).

(56) .sup.1H NMR (300 MHz, CD.sub.3CN) =9.18 (s, 1H), 8.51 (dd, J=8.4, 1.3 Hz, 1H), 7.72-7.50 (m, 7H), 7.50-7.38 (m, 4H), 4.25 (d, J=1.0 Hz, 3H); .sup.13C NMR (75 MHz, CD.sub.3CN) =167.44 (d, J.sub.C-P=35.6 Hz), 147.74, 141.70 (q, J.sub.C-F=3.0 Hz), 135.92 (d, J.sub.C-P=22.0 Hz), 134.82 (d, J.sub.C-P=1.2 Hz), 132.72, 131.05 (d, J.sub.C-P=8.6 Hz), 129.85 (q, J.sub.C-F=36.1), 129.43 (d, J.sub.C-P=6.0 Hz), 122.51 (q, J.sub.C-F=272.6 Hz), 49.24 (d, J.sub.C-P=20.7); .sup.19F NMR (282 MHz, CD.sub.3CN) =63.67, 151.79, 151.84; .sup.31P NMR (121 MHz, CD.sub.3CN) =6.00; IR (neat) {tilde over (v)}=693, 702, 727, 743, 752, 862, 892, 913, 996, 1048, 1090, 1115, 1148, 1174, 1267, 1342, 1435, 1504, 1579, 1639, 3103 cm.sup.1; HRMS calcd. for C.sub.19H.sub.16NF.sub.3P: 346.09727. found: 346.097027.

(57) ##STR00016##
Prepared by heating a THF suspension of 8 (500 mg, 2.14 mmol) and dicyclohexylphosphine (1.08 ml, 5.35 mmol) at 65 C. during 12 hours. White solid (648 mg, 77%).

(58) .sup.1H NMR (300 MHz, CDCl.sub.3) =9.06 (d, J=2.3 Hz, 1H), 8.34-8.21 (m, 1H), 8.21-8.08 (m, 1H), 4.64 (s, 3H), 2.12 (t, J=11.5 Hz, 2H), 1.98-1.61 (m, 8H), 1.52 (d, J=11.7 Hz, 2H), 1.44-1.02 (m, 10H); .sup.13C NMR (75 MHz, CD.sub.3CN) =160.88 (d, J.sub.C-F=255.9 Hz), 158.18 (dd, J.sub.C-P=43.7, J.sub.C-F=4.2 Hz), 140.06 (d, J.sub.C-P=36.1 Hz), 136.29 (dd, J.sub.C-P=7.4 Hz, J.sub.C-F=3.4 Hz), 131.93 (d, J.sub.C-P=17.2 Hz), 50.13 (d, J.sub.C-P=26.4 Hz), 34.72 (d, J.sub.C-P=14.3 Hz), 30.48 (d, J.sub.C-P=16.2 Hz), 30.01 (d, J.sub.C-P=8.7 Hz), 27.42 (d, J.sub.C-P=10.9 Hz), 27.28 (d, J.sub.C-P=10.9 Hz), 26.61; .sup.19F NMR (282 MHz, CDCl.sub.3) =118.61, 151.62, 151.67; .sup.31P NMR (121 MHz, CD.sub.3CN) =4.49; IR (neat) {tilde over (v)}=704, 738, 765, 817, 851, 889, 920, 958, 1004, 1025, 1040, 1057, 1112, 1170, 1182, 1202, 1269, 1279, 1433, 1450, 1504, 1582, 1626, 2852, 2925, 3077 cm.sup.1; HRMS calcd. for C.sub.18H.sub.17NP: 308.193442. found: 308.193793.

(59) ##STR00017##
Prepared by heating a THF suspension off 11 (500 mg, 2.05 mmol) and dicyclohexylphosphin (1.25 ml, 6.16 mmol) at 65 C. during 12 hours. White solid (744 mg, 89%).

(60) .sup.1H NMR (300 MHz, CDCl.sub.3) =8.48 (d, J=2.1 Hz, 1H), 8.04 (d, J=9.0 Hz, 1H), 7.94 (dd, J=9.0, 2.6 Hz, 1H), 4.43 (s, 3H), 4.01 (s, 3H), 2.21-2.08 (m, 2H), 1.85-0.96 (m, 20H); .sup.13C NMR (75 MHz, CD.sub.3CN) =159.15, 138.13, 135.35, 135.31, 58.35, 49.85 (d, J.sub.C-P=27.5 Hz), 34.82 (d, J.sub.C-P=13.5 Hz), 30.76 (d, J.sub.C-P=16.9 HZ), 29.97 (d, J.sub.C-P=8.1 Hz), 27.48 (d, J=13.2 Hz), 27.34 (d, J.sub.C-P=8.8 Hz), 26.73 (d, J.sub.C-P=1.1 Hz); .sup.19F NMR (282 MHz, CDCl.sub.3) =151.83, 151.88; .sup.31P NMR (121 MHz, CDCN) =7.27; IR (neat) {tilde over (v)}=704, 741, 816, 842, 884, 916, 1000, 1015, 1035, 1046, 1163, 1187, 1196, 1286, 1317, 1434, 1447, 1507, 1574, 1615, 2845, 2920 cm.sup.1; HRMS calcd. for C.sub.19H.sub.31NOP: 320.213778. found: 320.213335.

(61) ##STR00018##
To a suspension of KH (8.75 mg, 0.22 mmol) in THF (2 ml) was added bis(3,5-bis(trifluoromethyl)phenyl) phosphine (100 mg, 0.22 mmol) at 78 C. and the resulting deep red suspension stirred for 1 hour. Then, the suspension was transferred at the same temperature to a precooled suspension (78 C.) of 10 (64.9 mg, 0.22 mmol) in THF (2 ml) and the mixture allowed to warm up to rt and stirred for 3 days. After evaporation of the solvent and washing with DCM (22 ml), compound 19 was obtained as an off white solid (48 mg, 30%).

(62) .sup.1H NMR (300 MHz, CDCl.sub.3) =9.32 (s, 1H), 8.62 (d, J=7.7 Hz, 1H), 8.25 (s, 2H), 8.02 (d, J=7.2 Hz, 4H), 7.92 (d, J=7.9 Hz, 1H), 4.88 (m, 2H), 1.56 (t, J=7.3 Hz, 3H); .sup.13C NMR (75 MHz, CD.sub.3CN) =161.99 (d, J.sub.C-P=33.4 Hz), 147.95-146.40 (m), 143.99-142.39 (m), 137.44, 136.89-136.01 (m), 133.59 (qd, J.sub.C-F=33.9 Hz, J.sub.C-P=7.7 Hz), 133.19 (d, J.sub.C-P=13.5 Hz), 132.18 (d, J.sub.C-P=36.9 Hz), 124.10 (q, J.sub.C-F=272.4 Hz), 121.46 (q, J.sub.C-F=273.0 Hz), 58.60 (d, J.sub.C-P=23.4 Hz), 16.29 (d, J.sub.C-P=3.5 Hz); .sup.19F NMR (282 MHz, CDCl.sub.3) =63.52, 63, 68, 151.80, 151.85; .sup.31P NMR (121 MHz, CDCN) =10.52; IR (neat) {tilde over (v)}=682, 700, 741, 767, 846, 862, 900, 913, 1051, 1095, 1120, 1279, 1331, 1356, 1405, 1459, 1502, 1588, 1634, 2001, 3090 cm.sup.1; HRMS calcd. for C.sub.24H.sub.14F.sub.15NP: 632.062949. found: 632.061889.

(63) General Procedure for the Preparation of Pyridiniophosphine Rhodium Complexes

(64) [Rh(CO).sub.2Cl].sub.2 (0.25 equiv.) was added to a solution of the corresponding pyridiniophosphine ligand (1 equiv.) in DCM (2 ml). The resulting suspension was stirred for 1 hour at rt and after evaporation of the solvent, the solid was washed with n-pentan (22 ml) and dried in vacuum. These compounds can be crystallized from acetonitrile/ether mixtures.

(65) ##STR00019##
Prepared from 12 (100 mg, 0.274 mmol) and [Rh(CO)Cl.sub.2].sub.2 (26.6 mg, 0.063 mmol) following the general procedure. Yellow solid (121 mg, 99%).

(66) .sup.1H NMR (300 MHz, CDCN) =8.84 (d, J=5.9 Hz, 2H), 8.38 (t, J=7.7 Hz, 2H), 8.11-8.02 (m, 2H), 7.84 (s, 8H), 7.79-7.72 (m, 4H), 7.72-7.58 (m, 10H), 4.50 (s, 6H); .sup.13C NMR (75 MHz, CDCN) =186.07 (dt, J.sub.C-Rh=31.9 Hz, J.sub.C-P=15.6 Hz), 153.59 (t, J.sub.C-P=18.1 Hz), 151.14, 145.60, 136.20, 134.99, 134.20, 131.14, 130.07, 126.58 (t, J.sub.C-P=24.3 Hz), 50.82; .sup.31P NMR (121 MHz, CDCN) =37.82 (d, J.sub.P-Rh=130.7 Hz); IR (neat) {tilde over (v)}=692, 707, 752, 773, 799, 900, 931, 998, 1056, 1165, 1182, 1274, 1314, 1411, 1438, 1481, 1499, 1576, 1610, 1996, 3093, 3138 cm.sup.1; HRMS calcd. for C.sub.37H.sub.34BClF.sub.4N.sub.2OP.sub.2Rh: 809.092884. found: 809.093025.

(67) ##STR00020##
Prepared from 15 (75 mg, 0.2 mmol) and [Rh(CO).sub.2Cl].sub.2 (19.3 mg, 0.05 mmol) following the general procedure. Yellow solid (121 mg, 69%).

(68) .sup.1H NMR (300 MHz, CDCN) =8.98 (s, 2H), 8.27-8.16 (m, 2H), 7.84 (s, 8H), 7.76 (t, J=7.4 Hz, 4H), 7.68 (t, J=7.6 Hz, 10H), 4.54 (s, 6H); .sup.13C NMR (75 MHz, CDCN) =161.59 (d, J.sub.C-F=259.3 Hz), 150.65, 141.69 (d, J.sub.C-F=38.2 Hz), 136.72 (d, J.sub.C-P=8.5 Hz), 136.17, 134.35, 132.75 (d, J.sub.C-F=17.3 Hz), 131.22, 126.48, 51.51 (d, J.sub.C-P=1.6 Hz); .sup.31P NMR (121 MHz, CDCN) =39.02 (d, J.sub.Rh-P=130.7 Hz); IR (neat) {tilde over (v)}=694, 738, 754, 850, 962, 998, 1054, 1169, 1282, 1437, 1482, 1505, 1590, 1624, 1994, 3087 cm.sup.1; HRMS calcd. for C.sub.37H.sub.32BClF.sub.6N.sub.2OP.sub.2Rh: 845.074040. found: 845.073864.

(69) ##STR00021##
Prepared from 16 (100 mg, 0.231 mmol) and [Rh(CO).sub.2Cl].sub.2 (22.5 mg, 0.058 mmol) following the general procedure. Yellow solid (68 mg, 57%).

(70) .sup.1H NMR (300 MHz, CDCN) =9.28 (s, 2H), 8.65 (d, J=8.2 Hz, 2H), 7.95-7.63 (m, 22H), 4.56 (s, 6H); .sup.13C NMR (75 MHz, CDCN) =167.45 (d, J.sub.C-P=36.8 Hz), 147.80, 141.73, 136.46 (d, J.sub.C-P=22.1 Hz), 134.84, 132.76, 131.08 (d, J.sub.C-P=8.5 Hz), 129.81 (d, J.sub.C-P=36.7 Hz), 129.44 (d, J.sub.C-P=5.4 Hz), 122.54 (q, J.sub.C-F=272.8 Hz), 47.26 (d, J.sub.C-P=20.6 Hz); .sup.31P NMR (121 MHz, CDCN) =40.44 (d, J.sub.Rh-P=131.0 Hz); IR (neat) {tilde over (v)}=691, 705, 752, 858, 890, 932, 998, 1052, 1090, 1118, 1159, 1177, 1243, 1275, 1334, 1392, 1438, 1482, 1509, 1586, 1634, 1741, 2004, 3092 cm.sup.1; HRMS calcd. for C.sub.39H.sub.32BClF.sub.10N.sub.2OP.sub.2Rh: 945.067689. found: 945.067581.

(71) ##STR00022##
Prepared from 14 (100 mg, 0.253 mmol) and [Rh(CO).sub.2Cl].sub.2 (24.6 mg, 0.063 mmol) following the general procedure. Yellow solid (94 mg, 78%).

(72) .sup.1H NMR (300 MHz, CDCl.sub.3) =8.62 (d, J=5.6 Hz, 2H), 8.49 (t, J=7.9 Hz, 2H), 8.17-8.07 (m, 4H), 7.78 (dd, J=12.7, 6.3 Hz, 8H), 7.54 (ddd, J=22.9, 14.9, 7.8 Hz, 16H), 7.33 (t, J=7.5 Hz, 2H), 6.91 (t, J=8.0 Hz, 4H); .sup.13C NMR (101 MHz, CDCN) =154.96, 151.72, 146.24, 142.28, 136.52 (t, J.sub.C-P=7.2 Hz), 136.12-135.26 (m), 133.73, 132.75, 130.74 (t, J.sub.C-P=5.5 Hz), 130.48, 129.97, 128.15, 127.91, 127.71; .sup.31P NMR (121 MHz, CDCl.sub.3) =42.09 (d, J.sub.Rh-P=134.4 Hz); IR (neat) {tilde over (v)}=692, 749, 925, 998, 1034, 1048, 1182, 1254, 1286, 1318, 1437, 1457, 1479, 1587, 1603, 1981, 2350, 3060 cm.sup.1; HRMS calcd. for C.sub.47H.sub.38BClF.sub.4N.sub.2OP.sub.2Rh: 933.124354. found: 933.123835.

(73) ##STR00023##
Prepared from 18 (75 mg, 0.184 mmol) and [Rh(CO).sub.2Cl].sub.2 (17.9 mg, 0.046 mmol) following the general procedure. Yellow solid (67 mg, 74%).

(74) .sup.1H NMR (300 MHz, DMSO) =9.11 (s, 2H), 8.38 (d, J=9.1 Hz, 2H), 8.20 (dd, J=9.0, 2.3 Hz, 2H), 4.90 (s, 6H), 4.08 (s, 6H), 2.17 (s, 4H), 2.02-0.94 (m, 40H); .sup.13C NMR (101 MHz, DMSO) =185.13 (dt, J.sub.C-Rh=33.4 Hz, J.sub.C-P=16.4 Hz), 158.14, 140.35, 138.33 (t, J.sub.C-P=12.9 Hz), 134.89, 127.44, 57.59, 51.11 (t, J.sub.C-P=4.2 Hz), 36.04, 33.28, 29.39, 28.39, 27.61, 26.59, 25.77, 25.49; .sup.31P NMR (121 MHz, DMSO) =40.26 (d, J.sub.Rh-P=123.0 Hz); IR (neat) {tilde over (v)}=706, 739, 765, 815, 854, 888, 918, 940, 1018, 1050, 1098, 1172, 1180, 1207, 1269, 1317, 1415, 1450, 1475, 1515, 1614, 1974, 2850, 2928 cm.sup.1; HRMS calcd. for C.sub.39H.sub.62BClF.sub.4N.sub.2O.sub.3P.sub.2Rh: 893.301860. found: 893.302947.

(75) General Procedure for the Preparation of the Phosphine Platinum Complexes

(76) Finely grounded K.sub.2PtCl.sub.4 (1 equiv) was added to a solution of the pyridiniophosphine salt (1 equiv.) in MeCN (2 ml) and the resulting suspension stirred overnight at rt. After evaporation of the solvent, the solid was washed with n-Pentan (22 ml), crystallized from DMSO/DCM and dried in vacuum to yield the desired platinum complexes.

(77) ##STR00024##
Prepared from 12 (100 mg, 0.274 mmol) and K.sub.2PtCl.sub.4 (114 mg, 0.274 mmol) following the general procedure. White solid (127 mg, 80%).

(78) .sup.1H NMR (300 MHz, DMSO) =9.18 (d, J=5.7 Hz, 1H), 8.53 (t, J=7.9 Hz, 1H), 8.20 (t, J=6.9 Hz, 1H), 8.02 (dd, J=12.3 Hz, J=7.2 Hz, 4H), 7.79-7.57 (m, 6H), 7.39 (t, J=7.0 Hz, 1H), 4.35 (s, 3H); .sup.13C NMR (75 MHz, CD.sub.3CN) =150.13, 144.54 (d, J.sub.C-P=5.7 Hz), 135.32 (d, J.sub.C-P=11.6 Hz), 132.81 (d, J.sub.C-P=7.5 Hz), 132.63 (d, J.sub.C-P=2.5 Hz), 129.28 (d, J.sub.C-P=11.6 Hz), 128.78, 124.56, 123.71, 48.32 (d, J.sub.C-P=7.3 Hz); .sup.31P NMR (121 MHz, DMSO) =8.49 (J.sub.C-Pt=1954 Hz); IR (neat) {tilde over (v)}=673, 822, 1003, 1023, 1051, 1659, 2126, 2253, 2342, 2383 cm.sup.1; HRMS for DMSO adduct calcd. for C.sub.20H.sub.23Cl.sub.2NOPPtS: 621.024487. found: 621.024734.

(79) ##STR00025##
Prepared from 16 (100 mg, 0.231 mmol) and K.sub.2PtCl.sub.4 (96 mg, 0.231 mmol) following the general procedure. White solid (59 mg, 40%).

(80) .sup.1H NMR (300 MHz, DMSO) =9.85 (s, 1H), 8.98 (d, J=8.2 Hz, 1H), 8.05 (dd, J=12.4 Hz, J=7.4 Hz, 4H), 7.81-7.60 (m, 6H), 7.55 (dd, J=7.5 Hz, J=7.1 Hz, 1H), 4.42 (s, 3H); .sup.13C NMR (75 MHz, CD.sub.3CN) =155.07 (d, J.sub.C-P=46.9 Hz), 148.54, 141.59, 135.47 (d, J.sub.C-P=11.7 Hz), 133.48 (d, J.sub.C-P=7.7 Hz), 132.99, 129.46 (d, J.sub.C-P=11.6 Hz), 128.77 (d, J.sub.C-P=36.1 Hz), 123.54 (d, J.sub.C-P=64.0 Hz), 121.24 (q, J.sub.C-P=273.6 Hz), 49.19 (d, J.sub.C-P=6.8 Hz); .sup.31P NMR (121 MHz, DMSO) =10.63 (J.sub.C-Pt=1953 Hz); IR (neat) {tilde over (v)}=692, 704, 725, 755, 872, 890, 1036, 1114, 1148, 1179, 1192, 1270, 1332, 1388, 1438, 1481, 1508, 1631, 3001, 3044 cm.sup.1; HRMS for DMSO adduct calcd. for C.sub.21H.sub.22Cl.sub.2F.sub.3NOPPtS: 689.013152. found: 689.014029.

(81) General Procedure for the Preparation of the Phosphine Gold Complexes

(82) AuCl.SMe.sub.2 (1 equiv.) was added to a solution of the desired pyridiniophosphine salt (1 equiv.) in DCM (2 ml) and the resulting suspension stirred for 1 hour at rt. After evaporation of the solvent, the resulting solid washed with n-Pentan (22 ml) and dried in vacuum to yield the desired gold complexes.

(83) ##STR00026##
Prepared from 12 (100 mg, 0.274 mmol) and AuCl.SMe.sub.2 (80.7 mg, 0.274 mmol) following the general procedure. White solid (159 mg, 99%).

(84) .sup.1H NMR (300 MHz, CDCl.sub.3) =9.06 (d, J=0.5 Hz, 1H), 8.44 (t, J=7.7 Hz, 1H), 8.20 (t, J=6.4 Hz, 1H), 7.86-7.53 (m, 10H), 7.38 (t, J=7.5 Hz, 1H), 4.45 (s, 3H); .sup.13C NMR (75 MHz, CDCl.sub.3) =151.71, 147.12 (d, J.sub.C-P=52.2 Hz), 145.39 (d, J=5.6 Hz), 134.83 (d, J.sub.C-P25=15.6 Hz), 134.05 (d, J.sub.C-P=2.0 Hz), 133.77 (d, J.sub.C-P=9.3 Hz), 130.48 (d, J.sub.C-P=12.8 Hz), 122.55, 121.90, 48.64 (d, J.sub.C-P=11.4 Hz); .sup.31P NMR (121 MHz, CDCl.sub.3) =30.88; IR (neat) {tilde over (v)}=692, 729, 913, 998, 1055, 1097, 1162, 1185, 1278, 1438, 1482, 1500, 1609, 3061, 3138 cm.sup.1; HRMS calcd. for C.sub.18H.sub.17NAuClP: 510.044722. found: 510.044585.

(85) ##STR00027##
Prepared from 14 (50 mg, 0.12 mmol) and AuCl.SMe.sub.2 (34.5 mg, 0.12 mmol) following the general procedure. White solid (53 mg, 68%).

(86) .sup.1H NMR (400 MHz, CD.sub.3CN) =8.94 (s, 1H), 8.63 (t, J=8.0 Hz, 1H), 8.29 (t, J=6.7 Hz, 1H), 7.83-7.59 (m, 12H), 7.43 (t, J=8.0 Hz, 2H), 7.23 (d, J=7.9 Hz, 2H); .sup.13C NMR (101 MHz, CD.sub.3CN) =152.22, 148.28 (d, J.sub.C-P=5.2 Hz), 141.55 (d, J.sub.C-P.sup.=4.5 Hz), 136.26 (d, J.sub.C-P=15.9 Hz), 136.10 (d, J.sub.C-P=8.2 Hz), 134.89 (d, J.sub.C-P=2.5 Hz), 133.32, 131.31 (d, J.sub.C-P=3.2 Hz), 131.17, 131.01, 127.87, 125.84, 125.22; .sup.31P NMR (162 MHz, CD.sub.3CN) 6=31.36; IR (neat) {tilde over (v)}=668, 689, 712, 735, 753, 765, 786, 853, 926, 980, 997, 1030, 1044, 1099, 1144, 1162, 1189, 1256, 1283, 1433, 1442, 1458, 1483, 1587, 1603, 3060 cm.sup.1; HRMS calcd. for C.sub.23H.sub.19NAuClP: 572.060365. found: 572.060083.

(87) ##STR00028##
Prepared from 15 (100 mg, 0.26 mmol) and AuCl.SMe.sub.2 (76.6 mg, 0.26 mmol) following the general procedure. White solid (166 mg, 97%).

(88) .sup.1H NMR (400 MHz, CD.sub.3CN) =9.02 (dd, J=6.0 Hz, 2.7, 1H), 8.27 (ddd, J=9.1, 6.6, 2.6 Hz, 1H), 7.88-7.63 (m, 10H), 7.58-7.48 (m, 1H), 4.40 (s, 3H); .sup.13C NMR (101 MHz, CD.sub.3CN) =162.24 (d, J.sub.C-F=260.5 Hz), 142.99 (d, J.sub.C-P=37.3 Hz), 137.51 (dd, J.sub.C-F=10.0 Hz, J.sub.C-P=8.4 Hz), 136.23 (d, J.sub.C-P=15.9 Hz), 135.36 (d, J.sub.C-P=2.6 Hz), 133.81 (d, J.sub.C-P=6.2 Hz), 133.58 (d, J.sub.C-P=6.3 Hz), 131.65 (d, J.sub.C-P=12.8 Hz), 123.98 (d, J.sub.C-P=62.6 Hz), 50.70 (d, J.sub.C-P=11.9 Hz); .sup.31P NMR (162 MHz, CD.sub.3CN) =28.68; IR (neat) {tilde over (v)}=690, 717, 737, 751, 852, 964, 996, 1034, 1048, 1170, 1279, 1437, 1478, 1505, 1594, 1615, 3055, 3079 cm.sup.1; HRMS calcd. for C.sub.18H.sub.16NAuClFP: 528.035295. found: 528.035127.

(89) ##STR00029##
Prepared from 16 (100 mg, 0.23 mmol) and AuCl.SMe.sub.2 (68 mg, 0.23 mmol) following the general procedure. White solid (151 mg, 99%).

(90) .sup.1H NMR (300 MHz, CD.sub.3CN) =9.38 (s, 1H), 8.80-8.71 (m, 1H), 7.90-7.67 (m, 11H), 4.47 (s, 3H); .sup.13C NMR (75 MHz, CD.sub.3CN) =153.75 (d, J.sub.C-P=46.8 Hz), 150.38 (d, J.sub.C-P=2.5 Hz), 143.92 (td, J.sub.C-P=6.1, J.sub.C-F=3.0 Hz), 136.42 (d, J.sub.C-P=15.7 Hz), 136.41, 135.62 (d, J.sub.C-P=2.7 Hz), 133.42-131.99 (dq, J.sub.C-P=37.1 Hz, J.sub.C-F=1.6 Hz), 131.74 (d, J.sub.C-P=13.0 Hz), 123.16 (d, J.sub.C-P=64.7 Hz), 122.07 (q, J.sub.C-F=273.3 Hz), 50.82 (d, J.sub.C-P=11.3 Hz); .sup.19F NMR (282 MHz, CDCl.sub.3) =63.71, 151.49, 151.54; .sup.31P NMR (121 MHz, CD.sub.3CN) =31.54; IR (neat) {tilde over (v)}=691, 705, 715, 752, 873, 892, 996, 1053, 1118, 1162, 1200, 1280, 1334, 1393, 1440, 1481, 1510, 1590, 1634, 3092 cm.sup.1; HRMS calcd. for C.sub.20H.sub.18F.sub.3NP: 578.032104. found: 578.032257.

(91) ##STR00030##
Prepared from 19 (73 mg, 0.1 mmol) and AuCl.SMe.sub.2 (30 mg, 0.1 mmol) following the general procedure. White solid (37 mg, 38%).

(92) .sup.1H NMR (400 MHz, CD.sub.3CN) =9.44 (s, 1H), 8.78 (d, J=8.4 Hz, 1H), 8.45 (s, 2H), 8.30 (d, J=13.7 Hz, 4H), 7.92 (t, J=7.7 Hz, 1H), 4.83 (qd, J=7.0, 0.9 Hz, 2H), 1.64 (t, J=7.2 Hz, 3H); .sup.13C NMR (101 MHz, CD.sub.3CN) =149.17, 144.40 (dd, J.sub.C-P=5.9 Hz, J.sub.C-F=3.0 Hz), 138.49 (d, J.sub.C-P=9.6 Hz), 137.13 (d, J.sub.C-P=3.1 Hz), 136.96 (d, J.sub.C-P=3.1 Hz), 134.10 (qd, J.sub.C-F=34.5 Hz, J.sub.C-P=13.2 Hz), 134.00 (d, J.sub.C-P=37.3 Hz), 129.97 (d, J.sub.C-P=2.4 Hz), 126.61 (d, J.sub.C-P=60.9 Hz), 123.66 (q, J.sub.C-F=273.1 Hz), 122.00 (q, J.sub.C-F=273.6 Hz), 58.97 (d, J.sub.C-P=12.7 Hz), 16.49; .sup.19F NMR (282 MHz, CDCl.sub.3) =63.49, 63.59, 151.86, 151.90; .sup.31P NMR (162 MHz, CD.sub.3CN) =32.38; IR (neat) {tilde over (v)}=681, 699, 718, 731, 742, 764, 847, 866, 899, 927, 997, 1032, 1058, 1097, 1123, 1186, 1280, 1337, 1358, 1405, 1447, 1505, 1630, 3093 cm.sup.1; HRMS calcd. for C.sub.24H.sub.14NAuClF.sub.15P: 863.997295. found: 863.997181.

(93) As shown above, the inventors outlined herein the preparation of a new family of bench stable cationic phosphines, i.e. pyridiniophosphines, through a short and highly modular synthesis. The inventors have found out that their electronic properties evidenced weak -donor and quite strong -acceptor character when used as ancillary ligands. These attributes confer a substantially enhanced -acidity to the Pt(II) and Au(1) complexes thereof derived and, as result, the compounds depict an improved ability to activate alkynes towards nucleophilic attack. This superior performance has been demonstrated along several mechanistically diverse Pt(II) and Au(1) catalysed transformations. Thus, when used as ligands, the inventive compounds depict excellent -acceptor properties and, as consequence, a remarkable ability to enhance the Lewis acidity of the metals they coordinate. The beneficial effects of these properties in homogeneous catalysis have been demonstrated along three mechanistically diverse Pt(II)- and Au(I)-catalysed reactions.