5408 Organometallics, Vol. 23, No. 23, 2004
Itazaki et al.
NMR spectra (1H, 13C{1H}, and 31P{1H}) were recorded on
16.6, J(CP) ) 7.3 Hz, CO). IR (KBr, cm-1):1941 (ν(CO)). Anal.
Calcd for C57H53OP2Ir: C, 67.90; H, 5.30. Found: C, 67.77; H,
5.21.
JEOL EX-400 or Varian Mercury 300 spectrometers. Residual
1
peaks of solvent were used as the reference for H NMR (δ:
benzene-d6, 7.15; dichloromethane-d2, 5.32; toluene-d8, 2.09).
For 13C{1H} NMR, solvent signals were used as the chemical
shift reference, while 85% H3PO4 (δ 0) was used as the external
reference for 31P{1H} NMR. The IR spectra were recorded on
a Shimadzu FTIR-8100A spectrometer in KBr. Elemental
analyses were carried out with a Yanaco MT-5 CHN auto-
corder.
Thermal Reaction of 1. A benzene-d6 (0.6 mL) solution of
1 (17.2 mg, 0.02 mmol) in an NMR tube was heated at 55 °C.
1
After 9 h the H NMR measurements revealed that 1,1-bis-
(2-phenylethyl)-1,3-butadine was obtained in 47% yield, based
on tetramethylsilane as an internal standard.
Thermal Reaction of 2. A toluene-d8 (0.6 mL) solution of
isolated 2 (30.2 mg, 0.03 mmol) in an NMR tube was sealed
and heated at 110 °C. After 2 h, 3-methyl-3-vinyl-1,5-diphenyl-
1-pentene and 3-methyl-3-vinyl-1,5-diphenylpentane were ob-
tained in NMR yields of 48% and 15%, respectively. The yields
were determined by 1H NMR based on 2 using diphenyl-
methane as an internal standard. 1H NMR (300 MHz, toluene-
d8, 25 °C): 3-methyl-3-vinyl-1,5-diphenyl-1-pentene, δ 1.17 (s,
3H, Me), 1.72 (m, 2H, CH2), 2.52 (m, 2H, CH2), 5.04 (dd, J )
2, 17 Hz, 1H, CH2CH), 5.06 (dd, J ) 2, 11 Hz, 1H, CH2CH),
5.84 (dd, J ) 11, 17 Hz, 1H, CH2CH), 6.18 (d, 3J ) 17 Hz, 1H,
CH), 6.37 (d, 3J ) 17 Hz, 1H, CH); 3-methyl-3-vinyl-1,5-
diphenylpentane, δ 0.98 (s, 3H, Me), 1.54 (m, 4H, CH2), 2.45
(m, 4H, CH2), 4.94 (dd, J ) 2, 17 Hz, 1H, CH2CH), 5.06 (dd, J
) 2, 11 Hz, 1H, CH2CH), 5.67 (dd, J ) 11, 17 Hz, 1H, CH2CH).
Preparation of 3. To a solution of RhH(CO)(PPh3)3 (202
mg, 0.220 mmol) in toluene (7 mL) was added 2,2-bis(2-
phenylethyl)-1-methylenecyclopropane (231 mg, 0.880 mmol).
The solution gradually turned from orange to reddish orange
on stirring at 55 °C. After 4 h the volatiles were removed under
vacuum to give dark red oily substances, which were washed
with hexane at -78 °C repeatedly to give trans-Rh{(Z)-CHd
CHC(CH2CH2Ph)2CH3}(CO)(PPh3)2 (3) as an orange solid (180
mg, 0.196 mmol, 89%). Recrystallization of 3 from CH2Cl2-
hexane gave yellow crystals suitable for X-ray analysis. 1H
NMR (400 MHz, dichloromethane-d2, 25 °C): δ 0.85 (s, 3H,
CH3), 1.19-1.52 (m, 2H, PhCH2CH2), 1.28-1.36 (m, 2H,
PhCH2CH2), 2.12-2.16 (m, 4H, PhCH2CH2), 5.91 (d, J(HH) )
12.8 Hz, 1H, RhCHdCH), 6.15 (dt, J(HH) ) 12.8 Hz, J(PH) )
5.2 Hz, 1H, RhCH), 6.98-7.51 (m, 28H, Ph), 7.57-7.74 (m,
12H, Ph). 31P{1H} NMR (161.7 MHz, dichloromethane-d2, 25
°C): δ 30.84 (d, J(RhP) ) 168.0 Hz). 13C{1H} NMR (100.4 MHz,
dichloromethane-d2, 25 °C): δ 25.52 (CH3), 31.15 (PhCH2CH2),
39.12 (CCH3), 42.41 (PhCH2CH2), 125.42 (Ph para), 128.05 (t,
J(C-P) ) 5.0 Hz, PPh3 ortho), 128.33 (Ph ortho), 128.76 (Ph
meta), 129.79 (PPh3 para), 134.95 (t, J(CP) ) 6.6 Hz, PPh3
meta), 135.64 (t, J(CP) ) 19.0 Hz, PPh3 ipso), 144.62 (Ph ipso),
144.92 (t, J(CP) ) 4.1 Hz, RhCH ) CH), 159.21 (dt, J(RhC) )
23.2 Hz, J(CP) ) 16.6 Hz, RhC), the signal for a carbonyl
carbon was not observed. IR (KBr, cm-1): 1960 (ν(CO)). Anal.
Calcd for C57H53OP2Rh: C, 74.51; H, 5.81. Found: C, 74.79;
H, 6.16.
Preparation of 4. To a toluene (5 mL) solution of IrH(CO)-
(PPh3)3 (83 mg, 0.082 mmol) was added 2,2-bis(2-phenylethyl)-
1-methylenecyclopropane (44 mg, 0.168 mmol) at room tem-
perature. Stirring the solution at 115 °C caused the solution
to change from pale yellow to orange. After 12 h the volatiles
were removed under reduced pressure. Addition of 10 mL of
hexane to the resulting dark yellow oily residue at -78 °C led
to the formation of a pale yellow solid, which was washed with
10 mL of hexane (four times), collected by filtration, and dried
in vacuo to give a pale yellow powder of trans-Ir{(E)-CHdCH-
{C(CH2CH2Ph)2CH3}(CO)(PPh3)2 (4; 73 mg, 0.072 mmol, 88%).
Complex 4 crystallizes from dichloromethane-hexane at -20
°C as pale yellow crystals. 1H NMR (400 MHz, dichlo-
romethane-d2, 25 °C): δ 0.24 (s, 3H, CH3), 0.84-0.88 (m, 4H,
PhCH2CH2), 1.76-1.80 (m, 4H, PhCH2CH2), 4.40 (d, J(HH) )
18.4 Hz, 1H, IrCHdCH), 6.66 (d, J(HH) ) 18.4 Hz, 1H, IrCH),
6.71-6.73 (m, 4H, Ph), 7.06-7.17 (m, 6H, Ph), 7.31-7.38 (m,
18H, Ph), 7.68-7.69 (m, 12H, Ph). 31P{1H} NMR (161.7 MHz,
dichloromethane-d2, 25 °C): δ 5.19 (s). 13C{1H} NMR (100.4
MHz, dichloromethane-d2, 25 °C): δ 23.47 (CH3), 30.81
(PhCH2CH2), 41.84 (CCH3), 42.94 (PhCH2CH2), 125.28 (Ph
Preparation of 1. To a toluene (6 mL) solution of RhH-
(CO)(PPh3)3 (142 mg, 0.155 mmol) was added 2,2-bis(2-
phenylethyl)-1-methylenecyclopropane (45 mg, 0.171 mmol) at
room temperature. The solution immediately turned from
yellow to orange on stirring. After 1 h the volatiles were
removed under reduced pressure. The resulting orange oily
materials were washed with hexane repeatedly at -78 °C to
give Rh{η1:η2-CH2C(CH2CH2Ph)2CHdCH2}(CO)(PPh3)2 (1) as
a pale orange powder (127 mg, 0.138 mmol, 89%). Dissolving
the isolated 1 in a solvent at room temperature caused
immediate formation of butadiene derivatives and RhH(CO)-
(PPh3)3. Attempts to obtain crystals of 1 suitable for X-ray
analysis and elemental analyses were unsuccessful. 1H NMR
(400 MHz, dichloromethane-d2, -40 °C): δ -0.95 (partially
collapsed d, 1H, J ) 16.6 Hz, H4 or H5), 0.37 (t, 1H, J ) 5.4
Hz, H5 or H4), 0.91-0.98 (m, 1H, one of PhCH2CH2), 1.21-
1.28 (m, 1H, one of PhCH2CH2), 1.61 (t, 1H, J ) 7.1 Hz, H2),
1.86-2.00 (m, 3H, H1 and PhCH2CH2), 2.24-2.30 (m, 2H,
PhCH2CH2), 2.40 (m, 1H, H3), 2.44-2.56 (m, 2H, PhCH2CH2),
6.95-7.32 (m, 40H, Ph). 31P{1H} NMR (161.7 MHz, dichlo-
romethane-d2, -40 °C): δ 38.8 (dd, J(RhP) ) 90 Hz, J(PP) )
20 Hz), 26.9 (dd, J(RhP) ) 121 Hz, J(PP) ) 20 Hz). IR (KBr,
cm-1):1937 (ν(CO)).
Preparation of 2. To a toluene (5 mL) solution of IrH(CO)-
(PPh3)3 (120 mg, 0.119 mmol) was added 2,2-bis(2-phenyl-
ethyl)-1-methylenecyclopropane (34 mg, 0.131 mmol) at room
temperature. The resulting mixture was heated at 70 °C for 2
h, and the solution gradually turned from pale yellow to yellow
on stirring. The volatiles were removed by evaporation.
Addition of hexane (10 mL) to the resulting yellow oily
substance led to the formation of a pale yellow powder, which
was washed with 10 mL of hexane (four times), collected by
filtration, and dried in vacuo to give Ir{η1:η2-CH2C(CH2CH2-
Ph)2CHdCH2}(CO)(PPh3)2 (2; 111 mg, 0.110 mmol, 92%).
Complex 2 crystallized from CH2Cl2-hexane at 0 °C as
colorless crystals. 1H NMR (400 MHz, dichloromethane-d2, -40
°C): δ -0.66 (m, 1H, H4 or H5), 0.40 (m, 1H, H5 or H4), 1.10-
1.17 (m, 2H, H2 and one of PhCH2CH2), 1.34-1.43 (m, 2H, H1
and one of PhCH2CH2), 2.05-2.14 (m, 3H, H3 and PhCH2CH2),
2.14-2.36 (m, 2H, PhCH2CH2), 2.50-2.65 (m, 2H, PhCH2CH2),
7.05-7.36 (m, 40H, Ph). 31P{1H} NMR (161.7 MHz, dichlo-
romethane-d2, -40 °C): δ -7.66 (d, J(PP) ) 8 Hz), 8.17 (d,
J(PP) ) 8 Hz). 13C{1H} NMR (100.4 MHz, dichloromethane-
d2, 25 °C): δ -9.91 (d, J ) 60.6 Hz, IrC), 27.83 (PhCH2CH2),
29.44 (dd, J(CP) ) 9.1, J(CP) ) 3.6 Hz, C5), 32.00 (PhCH2CH2),
36.58 (d, J(CP) ) 23.9 Hz, C4), 40.66 (PhCH2CH2), 49.16 (dd,
J(CP) ) 5.5, J(CP) ) 3.7 Hz, C3), 49.86 (PhCH2CH2), 125.55
(Ph para), 125.80 (Ph para), 127.59 (d, J(CP) ) 9.1 Hz, PPh3
ortho), 128.09 (d, J(CP) ) 9.1 Hz, PPh3 ortho), 128.48 (Ph),
128.74 (Ph), 128.90 (Ph, 2 carbons), 129.36 (PPh3 para), 129.87
(PPh3 para), 133.84 (d, J(CP) ) 11.0 Hz, PPh3 meta), 134.68
(d, J(CP) ) 11.0 Hz, PPh3 meta), 134.46 (dd, J(CP) ) 40.4,
J(CP) ) 3.7 Hz, PPh3 ipso), 136.91 (d, J(CP) ) 36.7 Hz, PPh3
ipso), 144.49 (Ph ipso), 144.76 (Ph ipso), 187.06 (dd, J(CP) )
(19) (a) O’Connor, C.; Wilkinson, G. J. Chem. Soc. A 1968, 2665. (b)
Ahmad, N.; Levison, J. J.; Robinson, S. D.; Uttley, M. F. Inorg. Synth.
1974, 15, 45.
(20) (a) Yagupsky, G.; Wilkinson, G. J. Chem. Soc. A 1969, 725. (b)
Wilkinson, G.; Schunn, R. A.; Peet, W. G. Inorg. Synth. 1971, 13, 126.
(21) Arora, S.; Binger, P. Synthesis 1974, 801.