Dichloromethane

Pentane

Pyridine

3-Chloropyridine

Silver(I) trifluoromethansulfonate

[Rh(PPh₃)₂(CO)Cl] (ref 1)

[Rh(P(4-biphenyl)₃)₂(CO)Cl] [[808]]

[Rh(PCy₃)₂(CO)Cl] (ref 2)

[Ir(PPh₃)₂(CO)Cl] (ref 3)

[Ir(P(4-biphenyl)₃)₂(CO)Cl] [[808]]

[Ir(PCy₃)₂(CO)Cl] (ref 4)

A J. Young’s flask protected from light was charged with [M(PR₃)₂(CO)Cl] (ca. 100 mg, 1.0 eq.) and AgOTf (1.1 eq.). A solution of pyridine or 3-chloropyridine (5 eq.) in CH₂Cl₂ (5 mL) was added and the resulting mixture was stirred at room temperature for 1 hour. The solution was filtered to remove precipitated AgCl salts and the solvent removed in vacuo. The resulting yellow solid was washed with pentane (2 × 3 mL) and then recrystallized by slow diffusion of pentane into a CH₂Cl₂ solution of the compound.

[Rh(PPh₃)₂(CO)(py)]OTf (1a)

Yield = 55%.¹H NMR (500 MHz, CD₂Cl₂) δ 7.58 (d, J_HH = 5.4, 2H, py), 7.45-7.56 (m, 18H, Ph), 7.37-7.44 (m, 12H, Ph), 7.36 (d, J_HH = 8.4, 1H, py), 6.67 (t, J_HH = 6.8, 2H, py). ¹³C{¹H} NMR (126 MHz, CD₂Cl₂) δ 150.8, 138.7, 133.7, 131.3, 130.0 (t, J_PC = 24), 129.7, 126.3. The CO resonance was not unambiguously identified. ³¹P{¹H} NMR (122 MHz, CD₂Cl₂) δ 31.5 (d, J_RhP = 128). ESI-MS (180 °C, 4 kV): positive ion: 655.0840 m/z, [M-py]⁺ (calcd. 655.0821 m/z). IR (CH₂Cl₂, cm^-1): ν(CO) 2010. The solid-state structure of this compound has been deposited with the Cambridge Crystallographic Data Centre under CCDC 1498244. 

[Rh(PPh₃)₂(CO)(3-Clpy)]OTf (1b)

Yield = 38%. ¹H NMR (500 MHz, CD₂Cl₂) δ 7.75 (d, J_HH = 7.8, 1H, py), 7.48-7.61 (m, 18H, Ph), 7.43 (dd, J_HH = 8.5, 6.8, 12H, Ph), 7.37-7.29 (m, 2H, py), 6.76 (dd, J_HH = 8.2, 5.5, 1H, py). ¹³C{¹H} NMR (126 MHz, CD₂Cl₂) δ 190.1 (dt, J_RhC = 69, J_PC = 16), 149.7, 148.9, 138.3, 134.3 (t, J_PC= 7), 132.1, 130.3 (t, J_PC = 24), 129.7 (t, J_PC = 5) 126.7. ³¹P{¹H} NMR (122 MHz, CD₂Cl₂) δ 31.8 (d, J_RhP = 127). ESI-MS (180 °C, 4 kV): positive ion: 655.0833 m/z, [M-Clpy]⁺ (calcd. 655.0821 m/z). IR (CH₂Cl₂, cm^-1): ν(CO) 2013. The solid-state structure of this compound has been deposited with the Cambridge Crystallographic Data Centre under CCDC 1498245. 

 [Rh(P(4-biphenyl)₃)₂(CO)(py)]OTf (2a)

 Yield = 79%. ¹H NMR (500 MHz, CD₂Cl₂) δ 7.78 (d, J_HH = 5.3, 2H, py), 7.69-7.75 (m, 24H, Ar), 7.63-7.65 (m, 12H, Ar), 7.47-7.52 (m, 12H, Ar), 7.41-7.45 (m, 6H, Ar), 7.37 (t, J_HH = 7.7, 1H, py), 6.73 (t, 2H, J_HH = 6.8, py). ¹³C{¹H} NMR (126 MHz, CD₂Cl₂) δ 151.2, 144.7, 139.8, 138.5, 134.9 (t, J_PC = 7), 129.7, 129.3 (t, J_PC = 25), 129.0, 128.2 (t, J_PC = 5), 127.7, 126.4. The CO resonance was not unambiguously identified. ³¹P{¹H} NMR (202 MHz, CD₂Cl₂) δ 43.5 (d, J_RhP = 128). ESI-MS (180 °C, 4 kV): positive ion: 1111.2698 m/z, [M-py]⁺ (calcd. 1111.2699 m/z). IR (CH₂Cl₂, cm^-1): ν(CO) 2009. The solid-state structure of this compound has been deposited with the Cambridge Crystallographic Data Centre under CCDC 1498246. 

[Rh(P(4-biphenyl)₃)₂(CO)(3-Clpy)]OTf (2b)

Yield = 83%. ¹H NMR (500 MHz, CD₂Cl₂) δ 8.06 (d, J_HH = 5.5, 1H, py), 7.72-7.81 (m, 24H, Ar), 7.64-7.67 (m, 12H, Ar), 7.48-7.52 (m, 13H, Ar+py), 7.41-7.45 (m, 6H, Ar), 7.31 (d, J_HH = 8.3, 1H, py), 6.88 (dd, J_HH = 8.3, 5.5, 1H, py). ¹³C{¹H} NMR (176 MHz, CD₂Cl₂) δ 190.3 (dt, J_RhC= 69, J_PC = 17), 150.1, 149.3, 144.9, 139.9, 138.0, 134.9 (t, J_PC = 7), 134.1, 129.6, 129.0, 129.0 (t, J_PC = 24), 128.3 (t, J_PC = 5), 127.7, 127.0. ³¹P{¹H} NMR (202 MHz, CD₂Cl₂) δ 30.4 (d, J_RhP = 127). ESI-MS (180 °C, 4 kV): positive ion: 1111.2685 m/z, [M-py]⁺ (calcd. 1111.2699 m/z). IR (CH₂Cl₂, cm^-1): ν(CO) 1995. The solid-state structure of this compound has been deposited with the Cambridge Crystallographic Data Centre under CCDC 1498247. 

[Rh(PCy₃)₂(CO)(py)]OTf (3a)

Yield = 42%. ¹H NMR (500 MHz, CD₂Cl₂) δ 8.47 (d, 2H, J_HH = 7.3, py), 8.01 (t, 1H, J_HH = 8.0, py), 7.60-7.57 (m, 2H, py), 1.78-1.91 (m, 24H, Cy), 1.61-1.76 (m, 12H, Cy), 1.46-1.61 (m, 12H, Cy), 1.25 (qt, J_PH = 13.1, J_HH = 3.6, 6H, Cy), 1.04 (qt, J_PH = 13.0, J_HH = 3.3, 12H, Cy). ¹³C{¹H} NMR (126 MHz, CD₂Cl₂) δ 192.6 (dt, J_RhC = 69, J_PC = 16), 152.1, 140.1, 126.9, 35.4 (t, J_PC = 10), 31.0, 28.1 (t, J_PC = 5), 26.9. ³¹P{¹H} NMR (122 MHz, CD₂Cl₂) δ 33.1 (d, J_RhP = 118). ESI-MS (180 °C, 4 kV): positive ion: 691.3652 m/z, [M-py]⁺ (calcd. 691.3638 m/z). IR (CH₂Cl₂, cm^-1): ν(CO) 1983. The solid-state structure of this compound has been deposited with the Cambridge Crystallographic Data Centre under CCDC 1498248. 

[Rh(PCy₃)₂(CO)(3-Clpy)]OTf (3b) 

Yield = 19%. ¹H NMR (500 MHz, CD₂Cl₂) δ 8.51 (br, 1H, py), 8.40 (d, J_HH = 5.4, 1H, py), 8.04 (dd, J_HH = 8.4, J_HH = 1.5, 1H, py), 7.70 (dd, J_HH = 8.4, J_HH = 5.5, 1H, py), 1.80-1.93 (m, 24H, Cy), 1.75-1.64 (m, 12H, Cy), 1.46-1.62 (m, 12H, Cy), 1.31-1.21 (m, 6H, Cy), 1.13-0.98 (m, 12H, Cy). ¹³C{¹H} NMR (126 MHz, CD₂Cl₂) δ 192.3 (dt, J_RhC = 70, J_PC = 16), 150.7, 150.2, 140.0, 134.7, 128.0, 35.5 (t, J_PC = 10), 31.1 (d, J_PC = 16) 28.1 (m), 26.9. ³¹P{¹H} NMR (122 MHz, CD₂Cl₂) δ 33.1 (d, J_RhP = 117). ESI-MS (180 °C, 4 kV): positive ion: 691.3649 m/z, [M-py]⁺ (calcd. 691.3638 m/z). IR (CH₂Cl₂, cm^-1): ν(CO) 1986. The solid-state structure of this compound has been deposited with the Cambridge Crystallographic Data Centre under CCDC 1498249.

[Ir(PPh₃)₂(CO)(py)]OTf (4a)

Yield = 85%. ¹H NMR (500 MHz, CD₂Cl₂) δ 7.53-7.60 (m, 14H, Ph + py), 7.49 (t, J_HH = 7.4, 6H, Ph), 7.39-7.44 (m, 12H, Ph), 7.32 (t, J_HH = 7.8, 1H, py), 6.67-6.73 (m, 2H, py). ¹³C{¹H} NMR (126 MHz, CD₂Cl₂) δ 174.9 (t, J_PC = 11), 150.9, 139.3, 134.6 (t, J_PC = 6), 132.1, 130.1 (t, J_PC = 28), 129.6 (t, J_PC = 5), 126.8. ³¹P{¹H} NMR (122 MHz, CD₂Cl₂) δ 26.9. ESI-MS (180 °C, 4 kV): positive ion: 824.1821 m/z, [M]⁺ (calcd. 824.1820 m/z). IR (CH₂Cl₂, cm^-1): ν(CO) 2000. The solid-state structure of this compound has been deposited with the Cambridge Crystallographic Data Centre under CCDC 1498250.

[Ir(PPh₃)₂(CO)(3-Clpy)]OTf (4b)

Yield = 72%. ¹H NMR (500 MHz, CD₂Cl₂) δ 7.72 (d, J_HH = 5.6, 1H, py), 7.56-7.61 (m, 12H, Ph), 7.49-7.53 (m, 6H, Ph), 7.41-7.46 (m, 12H, Ph), 7.33 (d, J_HH = 8.4, 1H, py), 7.27 (d, J_HH = 2.3, 1H, py), 6.81 (dd, J_HH = 8.3, 5.6, 1H, py). ¹³C{¹H} NMR (126 MHz, CD₂Cl₂) δ 174.4 (t, J_PC = 11), 149.9, 149.0, 138.9, 134.5 (t, J_PC = 6), 132.3, 129.7, (t, J_PC = 28), 129.6 (t, J_PC = 5), 127.3. ³¹P{¹H} NMR (122 MHz, CD₂Cl₂) δ 27.2. ESI-MS (180 °C, 4 kV): positive ion: 745.1404 m/z, [M-py]⁺ (calcd. 745.1398 m/z). IR (CH₂Cl₂, cm^-1): ν(CO) 2003. The solid-state structure of this compound has been deposited with the Cambridge Crystallographic Data Centre under CCDC 1498251.

 [Ir(P(4-biphenyl)₃)₂(CO)(py)]OTf (5a)

Yield = 91%. ¹H NMR (500 MHz, CD₂Cl₂) δ 7.75-7.80 (m, 14H, Ar + py), 7.69-7.73 (m, 12H, Ar), 7.62-7.66 (m, 12H, Ar), 7.48-7.52 (m, 12H, Ar), 7.41-7.45 (m, 6H, Ar), 7.34-7.39 (m, 1H, py), 6.75-6.79 (m, 2H, py). ¹³C{¹H} NMR (176 MHz, CD₂Cl₂) δ 175.1 (t, J_PC = 11), 151.3, 144.9, 139.8, 139.0, 135.1 (t, J_PC = 6), 129.7, 129.0, 128.8 (t, J_PC = 28), 128.2 (t, J_PC = 5.8), 127.7, 126.9. ³¹P{¹H} NMR (202 MHz, CD₂Cl₂) δ 39.0. ESI-MS (180 °C, 4 kV): positive ion: 1242.3528 m/z, [M-py+MeCN]⁺ (calcd. 1242.3546 m/z). IR (CH₂Cl₂, cm^-1): ν(CO) 1999. The solid-state structure of this compound has been deposited with the Cambridge Crystallographic Data Centre under CCDC 1498252.

[Ir(P(4-biphenyl)₃)₂(CO)(3-Clpy)]OTf (5b)

Yield = 86%. ¹H NMR (500 MHz, CD₂Cl₂) δ 8.01 (d, J_HH = 5.5, 1H, py), 7.77-7.83 (m, 12H, Ar), 7.72-7.75 (m, 12H, Ar), 7.62-7.66 (m, 12H, Ar), 7.48-7.52 (m, 12H, Ar), 7.41-7.45 (m, 7H, Ar + py), 7.30 (d, J_HH = 8.5, 1H, py), 6.93 (dd, J_HH = 8.5, 5.5, 1H, py). ¹³C{¹H} NMR (176 MHz, CD₂Cl₂) δ 174.7 (t, J_PC = 12), 150.2, 149.5, 145.1, 139.8, 138.5, 135.1 (t, J_PC = 6), 134.7, 129.7, 129.1, 128.5 (t, J_PC = 27), 128.2 (t, J_PC = 5), 127.8, 127.6. ³¹P{¹H} NMR (202 MHz, CD₂Cl₂) δ 39.3. ESI-MS (180 °C, 4 kV): positive ion: 1242.3550 m/z, [M-py+CH₃CN]⁺ (calcd. 1242.3546 m/z). IR (CH₂Cl₂, cm^-1): ν(CO) 2002.

[Ir(PCy₃)₂(CO)(py)]OTf (6a)

Yield = 83%. ¹H NMR (400 MHz, CD₂Cl₂) δ 8.47 (d, 2H, J_HH = 5.2, py), 8.05 (t, J_HH = 7.6, 1H, py), 7.55-7.72 (m, 2H, py), 1.66-1.95 (m, 36H, Cy), 1.51-1.66 (m, 12H, Cy), 1.18-1.31 (m, Cy), 0.97-1.10 (m, 12H, Cy). ¹³C{¹H} NMR (101 MHz, CD₂Cl₂) δ 176.6 (t, J_PC = 11), 152.1, 140.7, 127.5, 35.5 (t, J_PC = 13), 30.9, 28.1 (t, J_PC = 5), 26.9. ³¹P{¹H} NMR (122 MHz, CD₂Cl₂) δ 28.4. ESI-MS (180 °C, 4 kV): positive ion: 781.4221 m/z, [M-py]⁺ (calcd. 781.4215 m/z). IR (CH₂Cl₂, cm^-1): ν(CO) 1975. The solid-state structure of this compound has been deposited with the Cambridge Crystallographic Data Centre under CCDC 1498253.

 [Ir(PCy₃)₂(CO)(3-Clpy)]OTf (6b)

Some of these complexes have been reported previously, e.g. 1a and 1b, C. Woods , C. Daffron, Inorg. Chim. Acta 1985, 101, 13-16 http://dx.doi.org/10.1016/S0020-1693(00)85619-4; 3a, J. Am. Chem. Soc. 1981, 103, 3411–3422 http://dx.doi.org/10.1021/ja00402a027