X. Li, J. Zhao, H. Zhang et al.
3.71 (s, 3H, NCH3), 2.62 (s, 3H, CH3), 2.12 (s, 3H, CH3), 2.03 ppm (s,
4.82 (br, 2H, COD), 4.52–4.58 (m, 2H, NCH2), 3.64 (septet, J=6.6 Hz,
1H, CH of iPr), 3.08–3.12 (m, 2H, PCH2), 2.96 (d, J=1.7 Hz, 2H,
CH2Ir), 2.85 (br, 2H, COD), 2.11–2.29 (m, 2H, COD), 1.98–2.13 (m, 4H,
COD), 1.71–1.80 (m, 2H, COD), 1.37 ppm (d, J=6.7 Hz, 6H, 2CH3);
31P{1H} NMR (121 MHz, [D6]acetone): d=13.2 (s, PPh2), À144.7 ppm
(septet, JP, F =705 Hz, PF6); 13C NMR (75 MHz, [D6]acetone): d=158.6 (s,
3H, CH3);. 31P{1H} NMR (121 MHz, CDCl3): d=À15.5 (s, PPh2);
13C NMR (75 MHz, CDCl3): d=143.6 (s, imidazole C2), 136.6 (d, JP, C
=
23.4 Hz, ipso-PPh2), 135.3 (d, JP, C =16.3 Hz, PPh2), 134.3 (s), 134.1 (d,
P, C =7.8 Hz, PPh2), 133.8 (d, JP, C =19.7 Hz, PPh2), 130.1 (s), 129.5 (s),
J
129.1 (s), 128.8 (d, JP, C =7.3 Hz, PPh2), 127.6 (d, JP, C =5.3 Hz, PPh2), 126.2
(s, imidazole C4/5), 125.6 (s, imidazole C4/5), 48.0 (d, JP, C =25.5 Hz,
imidazole C2), 133.3 (d, JP, C =10.9 Hz, o- or m-PPh2), 130.8 (d, JP,C
=
CH2), 33.0ACHTUNGTRENNUNG(s, NCH3), 11.7 (s, CH3), 9.10 (s, CH3), 8.92 ppm (s, CH3). No
2.1 Hz, p-PPh2), 130.4 (d, JP, C =49.1 Hz, ipso-PPh2), 128.6 (d, JP,C =9.9 Hz,
o- or m-PPh2), 118.7 (s, C4/5), 113.8 (s, C4/5), 88.5 (d, JP, C =13.2 Hz, CH
of COD), 64.1 (s, CH of COD), 49.1 (s, CH of iPr), 42.7 (s, NCH2), 31.6
(d, JP, C =2.8 Hz, CH2 of COD), 30.5 (s, CH2 of COD), 21.4 (s, CH3), 19.5
(d, JP, C =29.5 Hz, PCH2), 13.9 ppm (d, JP, C =4.9 Hz, IrCH2); elemental
analysis (%) calcd for C29H37F6IrN2P2 (781.8): C 44.55, H 4.77, C 3.58;
found: C 44.72, H 4.67, C 3.68.
satisfactory microanalysis could be obtained for ligand 7-Cl due to its hy-
À
groscopicity. The microanalysis of the PF6 analogue gave satisfactory
data (see compound 7).
Compound 7: Compound 7 was synthesized as a white solid in 94% yield
by a method directly analogous to that for 1b. 1H NMR (300 MHz,
CDCl3): d=7.30–7.46 (m, 6H), 7.21–7.25 (m, 6H), 6.91–6.97 (m, 2H),
5.31 (s, 2H, CH2), 3.54 (s, 3H, NCH3), 2.37 (s, 3H, CH3), 2.14 (s, 3H,
CH3), 2.02 ppm (s, 3H, CH3); 31P{1H} NMR (161 MHz, CDCl3): d=À16.2
(s, PPh2), À144.7 ppm (septet, JP, F =710 Hz, PF6); 13C NMR (100 MHz,
CDCl3): d=142.8 (s, imidazole C2), 136.3 (d, JP,C =23.3 Hz, ipso-PPh2),
135.1 (d, JP, C =16.2 Hz, PPh2), 134.2 (s), 134.0 (d, JP, C =6.2 Hz, PPh2),
133.8 (d, JP, C =19.7 Hz, PPh2), 130.4 (s), 129.6 (s), 129.1 (s), 128.8 (d,
Complex 3a. Complex 3a was synthesized as a yellow solid by following
method 1 or 2. Yield: 92% (61 mg, 0.0918 mmol, method 2). Single crys-
tals of 3a suitable for X-ray analysis were obtained by slow diffusion of
diethyl ether to a solution in THF after 2 d at room temperature.
1H NMR (300 MHz, CD2Cl2): d=7.40–7.51 (m, 10H, PPh2), 6.46 (d, J=
2.2 Hz, 1H, imidazole H4/5), 6.03 (d, J=2.0 Hz, 1H, imidazole H4/5),
5.16–5.18 (m, 2H, COD), 4.26–4.34 (m, 2H, NCH2), 3.37–3.38 (m, 2H,
COD), 3.35 (s, 3H, NCH3), 2.60–2.67 (m, 2H, PCH2), 2.43–2.49 (m, 2H,
COD), 2.23–2.33 (m, 4H, COD), 2.08–2.09 (m, 2H. RhCH2), 2.02–2.04
(m, 1H, COD), 1.83–1.87 ppm (m, 1H, COD); 31P{1H} NMR (121 MHz,
CD2Cl2): d=24.5 (d, JRh,P =164.9 Hz, PPh2), À143.8 (septet, JP, F =708 Hz,
PF6); 13C NMR (75 MHz, CD2Cl2): d=159.2 (s, imidazole C2), 133.1 (d,
J
P, C =7.3 Hz, PPh2), 127.0 (d, JP, C =5.1 Hz, PPh2), 126.5 (s, imidazole C4/
5), 125.6 (s, imidazole C4/5), 48.0 (d, JP,C =25.5 Hz, CH2), 32.0 (s, NCH3),
10.4 (s, CH3), 8.86 (s, CH3), 8.58 ppm (s, CH3); elemental analysis (%)
calcd for C26H28F6N2P2 (544.5): C 57.36, H 5.18, C 5.15; found: C 57.29, H
5.11, C 5.09.
General synthetic methods for 2-methyleneimidazoline complexes:
J
J
P, C =11.9 Hz, o- or m-PPh2), 130.9 (d, JP, C =1.9 Hz, p-PPh2), 130.8 (d,
P, C =40.3 Hz, ipso-PPh2), 128.5 (d, JP, C =9.6 Hz, o- or m-PPh2), 118.2 (s,
Method 1: Phosphine imidazolium ligand (0.2 mmol) was added to a so-
lution of [{MACHTUNGTRENNUNG(cod)Cl}2] (M=Rh, Ir; 0.1 mmol) or [PdAHCUTTGNREN(NUNG allyl)Cl]2 in THF
imidazole C4/5), 116.7 (s, imidazole C4/5), 100.5 (dd,
Rh,C =8.0 Hz, CH of COD), 80.7 (d, JRh,C =9.2 Hz, CH of COD), 42.9 (s,
NCH2), 34.0 (s, CH3), 31.5 (d, JP, C =2.3 Hz, CH2 of COD), 30.0 (s, CH2 of
COD), 21.1 (d, JP, C =21.6 Hz, PCH2), 10.0 ppm (dd, JP, C =8.0 Hz, JRh,C
20.2 Hz, RhCH2); elemental analysis (%) calcd for C27H33F6N2P2Rh
(664.4): C 48.81, H 5.01, C 4.22; found 48.69, H 5.14, C 4.09.
JP,C =10.8 Hz,
(6 mL). The resulting solution was stirred at RT for 30 min. The solution
was then cooled to À788C, and tBuOK (1m THF solution, 0.21 mmol)
was added. The mixture was stirred at À788C for 2 h and was slowly
warmed to RT. All volatile substances were then removed under reduced
pressure. CH2Cl2 (5 mL) was added to the residue, and the inorganic salt
removed by filtration through Celite. The solution obtained was then
J
=
concentrated to ca. 0.5 mL, followed by washing with pentane (2
5 mL) to give the final product.
ꢂ
Complex 3b: Complex 3b was synthesized as a yellow solid by following
method 1 or 2. Yield: 91% (63 mg, 0.091 mmol, method 2). 1H NMR
(300 MHz, CD2Cl2): d=7.40–7.53 (m, 10H, PPh2), 6.64 (d, J=2.3 Hz,
1H, imidazole H4/5), 6.35 (d, J=2.3 Hz, 1H, imidazole H4/5), 5.12 (br,
2H, COD), 4.27–4.34 (m, 2H, NCH2), 4.21 (septet, J=6.7 Hz, 1H, CH of
iPr), 3.40–3.41 (m, 2H, COD), 2.62–2.69 (m, 2H, PCH2), 2.42–2.50 (m,
2H, COD), 2.26–2.30 (m, 4H, COD), 2.13 (apparent t, J=2.6 Hz, 2H,
RhCH2), 1.99–2.11 (m, 1H, COD), 1.83–1.86 (m, 1H, COD), 1.38 ppm
(d, J=6.7 Hz, 6H, CH3); 31P{1H} NMR (121 MHz, CD2Cl2): d=21.0 (d,
Method 2: tBuOK (0.11 mL, 1m in THF, 0.11 mmol) was slowly added to
a solution of [{M(cod)Cl}2](M=Rh, Ir; 0.05 mmol) in THF (5 mL). The
ACHTUNGTRENNUNG
solution was stirred for 2 h followed by addition of a suspension of a
phosphine imidazolium salt (0.1 mmol) in THF. The mixture was stirred
at room temperature for another 6 h, followed by removal of all volatiles
under reduced pressure. CH2Cl2 (5 mL) was added to the residue, and
the inorganic salt removed by filtration through Celite to give a solution.
The solvent was removed and the residue washed with pentane or Et2O
(3ꢂ5 mL) to give the final products.
J
Rh,P =165.2 Hz, PPh2), À143.8 ppm (septet, JP,F =708 Hz, PF6); 13C NMR
(75 MHz, CD2Cl2): d=157.9 (s, imidazole C2), 133.1 (d, JP,C =11.6 Hz, o-
or m-PPh2), 131.0 (d, JP, C =39.2 Hz, ipso-PPh2), 130.7 (d, JP, C =2.0 Hz, p-
PPh2), 128.7 (d, JP, C =9.5 Hz, o- or m-PPh2), 118.0 (s, imidazole C4/5),
113.2 (s, imidazole C4/5), 99.9 (dd, JP,C =10.8 Hz, JRh,C =8.1 Hz, CH of
COD), 81.1 (d, JRh,C =9.1 Hz, CH of COD), 49.1 (s, CH of iPr), 42.7 (s,
NCH2), 31.4 (d, JP, C =2.4 Hz, CH2 of COD), 30.5 (s, CH2 of COD), 21.8
Complex 2a: Complex 2a was synthesized as a red solid by following
method 1 or 2. Yield: 91% (68.5 mg, 0.091 mmol, method 2). Single crys-
tals of 2a suitable for X-ray analysis were obtained by slow diffusion of
diethyl ether to a solution in CH2Cl2 after 7 days at À208C. 1H NMR
(300 MHz, [D6]acetone): d=7.47–7.55 (m, 10H, PPh2), 6.81 (d, J=
2.2 Hz, 1H, imidazole H4/5), 6.38 (d, J=2.1 Hz, 1H, imidazole H4/5),
4.83–4.86 (m, 2H, COD), 4.48–4.58 (m, 2H, NCH2), 3.62 (s, 3H, NCH3),
3.04–3.11 (m, 2H, PCH2), 2.88 (d, J=1.6 Hz, 2H, CH2Ir), 2.81–2.83 (m,
2H, COD), 2.21–2.31 (m, 2H, COD), 1.95–2.15 (m, 4H, COD), 1.66–
1.75 ppm (m, 2H, COD); 31P{1H} NMR (121 MHz, [D6]acetone): d=15.4
(s, PPh2), À143.6 ppm (septet, JP, F =703.8 Hz, PF6); 13C NMR (100 MHz,
[D6]acetone): d=159.9 (s, imidazole C2), 133.5 (d, JP,C =13.0 Hz, o- or m-
PPh2), 130.9 (d, JP, C =2.0 Hz, p-PPh2), 130.3 (d, JP, C =49.3 Hz, ipso-PPh2),
128.4 (d, JP,C =10.0 Hz, o- or m-PPh2), 118.7 (s, imidazole C4/5), 117.4 (s,
imidazole C4/5), 88.9 (d, JP, C =10.0 Hz, CH of COD), 63.7 (s, CH of
COD), 42.8 (s, NCH2), 33.5 (s, NCH3), 31.7 (d, JP, C =3.0 Hz, CH2 of
COD), 30.4 (s, CH2 of COD), 20.1 (d, JP, C =29.4 Hz, PCH2), 13.9 ppm (d,
(s, CH3), 20.8 (d, JP, C =21.7 Hz, PCH2), 9.8 ppm (dd, JP, C =8.2 Hz, JRh,C
=
20.9 Hz, RhCH2); elemental analysis (%) calcd for C29H37F6N2P2Rh
(692.5): C 50.30, H 5.39, C 4.05; found: C 50.42, H 5.28, C 4.17.
Complex 3c. Complex 3c was synthesized as a yellow solid by following
method 1 or 2. Yield: 94% (65.1 mg, 0.094 mmol, method 2). 1H NMR
(400 MHz, CD2Cl2): d=7.42–7.48 (m, 10H, PPh2), 5.17 (br, 2H, COD),
4.29–4.36 (m, 2H, NCH2), 3.35 (br, 2H, COD), 3.19 (s, 3H, CH3), 2.61–
2.65 (m, 2H, PCH2), 2.46–2.49 (m, 2H, COD), 2.24–2.31 (m, 4H, COD),
2.08 (m, 2H, RhCH2), 2.03–2.06 (m, 1H, COD), 1.88 (s, 3H, CH3), 1.84–
1.87 (m, 1H, COD), 1.57 ppm (s, 3H, CH3); 31P{1H} NMR (161 MHz,
CD2Cl2): d=23.1 (d, JRh,P =165.7 Hz, PPh2), À144.5 (septet, JP, F =707 Hz,
PF6); 13C NMR (100 MHz, CD2Cl2): d=158.5 (s, imidazole C2), 133.1 (d,
J
P, C =5.0 Hz, IrCH2); elemental analysis (%) calcd for C27H33F6IrN2P2
J
P, C =11.9 Hz, o- or m-PPh2), 131.0 (d, JP, C =40.3 Hz, ipso-PPh2), 130.8 (s,
(753.7): C 43.03, H 4.41, C 3.72; found: C 43.39, H 4.53, C 3.91.
p-PPh2), 128.4 (d, JP,C =9.5 Hz, o- or m-PPh2), 121.2 (s, imidazole C4/5),
120.2 (s, imidazole C4/5), 100.7 (dd, JP, C =10.7 Hz, JRh,C =8.0 Hz, CH of
COD), 80.5 (d, JRh,C =9.0 Hz, CH of COD), 39.7 (s, NCH2), 31.5 (br, CH2
of COD), 30.4 (s, CH3), 30.4 (s, CH2 of COD), 20.8 (d, JP, C =22.0 Hz,
Complex 2b: Complex 2b was synthesized as a red solid by following
method 1 or 2. Yield: 88% (68.7 mg, 0.088 mmol, method 2). 1H NMR
(400 MHz, [D6]acetone): d=7.48–7.58 (m, 10H, PPh2), 6.97 (d, J=
2.0 Hz, 1H, imidazole H4/5), 6.78 (d, J=2.0 Hz, 1H, imidazole H4/5),
PCH2), 10.9 (dd,
J
P, C =7.9 Hz,
J
Rh,C =20.7 Hz, RhCH2), 7.6 (s, CH3),
5542
ꢀ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2009, 15, 5535 – 5544