992 Organometallics, Vol. 19, No. 6, 2000
Davies et al.
mg, 80% yield). For smaller scale reactions it was not necessary
to add a proton source to the reaction mixture in order to
isolate the neutral product. Instead the mixture was filtered
through silica and repeatedly washed with CH2Cl2 to yield 3.
Slow diffusion of hexane into a CH2Cl2 solution of 3 yielded
green-brown crystals suitable for X-ray diffraction. IR: ν(CO)
1958 (vs), 1910 (m), 1851 cm-1 (m). 1H NMR: δ 7.6-7.0 (m,
Hz, Ph2PCH2CH2COOMe). Anal. Calcd for C29H27Mo2O5P3: C,
47.05; H, 3.68; P, 12.55. Found: C, 47.59; H, 3.73; P, 11.95.
FAB-MS: m/z M+ 739.
(b) Acr ylon itr ile. The same procedure was followed for the
reaction of 2 with acrylonitrile; a 10% excess of acrylonitrile
was added to a solution of 2, to yield after 3:2 CH2Cl2-hexane
elution on TLC plates 1 (12 mg, 8%) and orange crystalline
[Cp2(CO)3Mo2(µ-η2-P2)(PPh2C2H4CN)] (5b; 146 mg, 85%). Slow
evaporation of a hexane/CH2Cl2 solution yielded orange crys-
tals suitable for X-ray diffraction. IR: ν(CO) 1957 (s), 1902
(vs), 1868 (s, sh). 1H NMR: δ 7.75-7.21 (m, 10H, Ph), 5.12 (s,
2
10H, Ph), 5.52 (ddd, 1H, J P-H ) 24, 4, 4 Hz, S2CH), 5.24 (s,
1
5H, Cp), 5.16 (s, 5H, Cp). 31P{1H} NMR: δ 205.45 (d, J P-P
)
446 Hz, Mo-PdPS2CH), 145.65 (s, PPh2), -0.25(d, 1J P-P ) 446
Hz, Mo-PdPS2C). 13C NMR: δ 242.3 (s, CO), 134-127 (m,
Ph), 89.8 (s, Cp), 84.2 (s, Cp), 63.9 (d, 1J P-C ) 41 Hz, Ph2PC(H)-
S2). Anal. Calcd for C26H21Mo2O3P3S2‚1/2CH2Cl2: C, 41.18; H,
2.87; P, 12.02. Found: C, 40.43; H, 2.82; P, 11.37. FAB-MS:
m/z 730 (M+).
3
5H, Cp), 4.63 (d, J P-H ) 1.9 Hz, 5H, Cp), 2.93-2.64 (m, 2H,
PCH2), 2.38-2.03 (m, 2H, PCH2CH2). 31P{1H} NMR: δ 50.88
1
(s (b), Ph2PC2H4CN), -36,60 (d, J P-P ) 476.5 Hz, cis-µ-η2-
1
P2), -42.62 (d, J P-P ) 476.5 Hz, trans-µ-η2-P2). 13C NMR: δ
Rea ction of [Cp 2(CO)3Mo2(µ-η2-P 2)(P P h 2)]- (2) w ith
3-ClC6H4NCO. To a solution of 2 (250 mg, 38 mmol) was
added 3-ClC6H4NCO (11.67 mg, 2 equiv), and the solution was
stirred overnight. The solution was then filtered through a
silica pad and the solvent removed under reduced pressure,
after which the residue was redissolved in the minimum
amount of CH2Cl2 and applied to the base of TLC plates.
Elution with a 3:2 CH2Cl2-hexane mixture yielded the starting
material 1 (22 mg, 9%) and orange crystalline [Cp2(CO)3Mo2-
(µ-η2-P2)(P(Ph)2C(O)NH3-ClC6H4)] (4a ; 240 mg, 80%). IR: ν-
(CO) 1961 (vs), 1897 cm-1 (s). 1H NMR: δ 9.3 (s, 1H, NH),
243.84 (s, CO), 231.75 (s, CO), 223.24 (s, CO), 138.924-125.737
1
(m, Ph), 86.485 (s, Cp), 85.39 (s, Cp) 32.38 (d, J P-C ) 45.5,
2
Ph2PCH2R), 14.44 (d, J P-C ) 16 Hz, Ph2PCH2CH2CN). Anal.
Calcd for C28H24Mo2NO3P3: C, 47.55; H, 3.42; N, 1.98; P, 13.14.
Found: C, 47.44; H, 3.34; N, 1.94; P, 13.27. FAB-MS: m/z
709.7 (M+), 656.5 (M+ - 2CO).
(c) MVK. The same reaction was repeated using a 10%
excess of MVK as the Michael acceptor, to yield, after elution
with 3:2 CH2Cl2-hexane on TLC plates, trace 1 and orange
crystalline [Cp2(CO)3Mo2(µ-η2-P2)(PPh2C2H4C(dO)Me)] (5c;
116 mg, 68%). IR: ν(CO) 1958 (s), 1891 (vs), 1864 cm-1 (s, sh).
1H NMR: δ 7.82-7.18 (m, 10H, Ph), 5.08 (s, 5H, Cp), 4.57 (d,
3J P-H ) 1.7 Hz, 5H, Cp), 3.65-3.40 (m, 2H, PCH2), 2.92-2.48
(m, 2H, PCH2CH2), 2.0 (s, 3H, COCH3). 31P{1H} NMR: δ 50.12
3
7.88-7.09 (m, 14H, Ph), 5.11 (s, 5H, Cp), 4.69 (d, J P-H ) 1.9
Hz, 5H, Cp). 31P{1H} NMR: δ 66.98 (dd, 2J P-P ) 30.8 Hz, 2J P-P
) 7.6 Hz, PPh2C(O)NH3-ClPh), -30.27 (dd, 1J P-P ) 473.4 Hz,
1
2J P-P ) 30.8 Hz, trans-µ-η2-P2), -46.40 (dd, J P-P ) 473.4 Hz,
1
(s, Ph2PC2H4COMe), -34.39 (d, J P-P ) 479 Hz, trans-µ-η2-
2J P-P ) 7.6 Hz, cis-µ-η2-P2). 13C NMR: δ 229 (CO), 205 (CO),
189 (Ph2PC(O)NH), 136-122 (m, Ph), 88.3 (s, 5H, Cp), 87.1
(s, 5H, Cp). Anal. Calcd for C32ClH25Mo2NO4P3: C, 47.58; H,
3.12; P, 11.5; N, 1.73. Found: C, 46.8; H, 3.19; P, 11.57; N,
1.59. FAB-MS: m/z 807 (M+).
P2), -41.81 (d, 1J P-P ) 479 Hz, cis-µ-η2-P2). 13C NMR: δ 243.1
(s, CO), 223.14 (s, CO), 223.841 (s, CO), 206.56 (d, 3J P-C ) 10.7
Hz, Ph2C2H4C(O)Me), 140.3-128.15 (m, Ph), 86.53 (s, Cp),
1
85.27 (s, Cp), 30.03 (s, COCH3), 29.45 (d, J P-C ) 28 Hz,
2
Ph2PCH2), 29.08 (d, J P-C ) 18.5 Hz). Anal. Calcd for C29H27
-
Rea ction of [Cp 2(CO)3Mo2(µ-η2-P 2)(P P h 2)]- (2) w ith
P h NCS. The same procedure as in the previous paragraph
was applied using a 2-fold excess of PhNCS to yield, after
elution with 3:2 hexane-CH2Cl2, orange crystalline [Cp2(CO)3-
Mo2(µ-η2-P2)(PPh2C(S)NHPh)] (4b; 256 mg, 85% yield) as the
sole product. IR: ν(CO) 1961 (vs), 1897 (s), 1874.5 cm-1 (s, sh).
1H NMR: δ 8.80 (s, 1H, NH), 7.92-7.2 (m, 15H, Ph), 5.12 (s,
Mo2O4P3: C, 48.09; H, 3.76; P, 12.83. Found: C, 47.71; H, 3.63;
P, 12.53. FAB-MS: m/z 726.8 (M+).
Reaction of [Cp2(CO)3Mo2(µ-η3-P h 2P C(H)SP 2S)] (3) with
tBu Li a n d MeI. A solution of 3 (250 mg, 0.34 mmol) in THF
t
(50 mL) was cooled to -78 °C, and a 1.7 M solution of BuLi
(0.2 mL, 1.1 equiv) was added over 10 min, during which time
the color changed to deep orange. To the resulting mixture
MeI was added (53 mg, 1.1 equiv), and the solution was stirred
for 1/2 h at -78 °C, during which time the color changed from
orange to purple. The resulting solution was filtered through
a pad of silica and solvent removed in vacuo to yield purplee-
brown [Cp2(CO)3Mo2(µ-η2-P2)(Ph2PC(S)SMe)] (6) as the sole
product (182 mg, 72%). IR: ν(CO) 1957 (s), 1892 (vs), 1863
(m, sh) cm-1. 1H NMR: δ 7.85-7.38 (m, 10H, Ph), 5.07 (s, 5H,
3
5H, Cp), 4.68 (d, J P-H ) 1.7 Hz, 5H, Cp). 31P{1H} NMR: δ
2
88.94 (dd, J P-P ) 23.6, 7.4 Hz, PPh2PhC(S)NH), -19.69 (dd,
2
1J P-P ) 476 Hz, J P-P ) 23.6 Hz, trans-µ-η2-P2), -40.63 (dd,
2
1J P-P ) 467 Hz, J P-P ) 7.4 Hz, cis-µ-η2-P2). Anal. Calcd for
C
32H26Mo2NO3P3S: C, 48.69; H, 3.32; P, 11.77; N, 1.85.
Found: C, 47.96; H, 3.13; P, 11.12; N, 1.85. FAB-MS: m/z
792.9 (M+).
3
Cp), 4.6 (d, J P-H ) 1.8 Hz, 5H, Cp), 2.30 (s, 3H, SCH3). 31P-
Rea ction of [Cp 2(CO)3Mo2(µ-η2-P 2)(P P h 2)]- (2) w ith
Mich a el Accep tor s. Meth yl Acr yla te. To a solution of 2 (150
mg, 0.22 mmol) was added methyl acrylate (0.25 mL, 0.27
mmol), and the mixture was stirred for 2 h, during which time
the solution color changed from orange-brown to deep orange,
after which a slight deficiency of 85% HBF4‚OEt2 (37 mg, 0.85
equiv) was added. The solvent was removed in vacuo, redis-
solved in the minimum amount of CH2Cl2, and applied to the
base of TLC plates. Elution with 3:2 hexane-CH2Cl2 yielded,
in addition to a trace of starting material 1, orange crystalline
[Cp2(CO)3Mo2(µ-η2-P2)(PPh2C2H4COOMe)] (5a ), in 70% yield.
Slow evaporation of a CH2Cl2-hexane solution yielded orange
crystals of suitable quality for X-ray diffraction analysis. IR:
2
2
{1H} NMR: δ 100.43 (dd, J P-P ) 18.2 Hz, J P-P ) 5.2 Hz,
Ph2PCS2Me), -7.32 (dd, 1J P-P ) 484.6 Hz, 2J P-P ) 18.2, trans-
µ-η2-P2), -20.32 (dd, J P-P ) 484.6 Hz, J P-P ) 5.2, cis-µ-η2-
P2). Anal. Calcd for C27H23Mo2O3P3S2: C, 43.57, H, 3.11, P,
12.48. Found: C, 43.04, H, 3.46, P, 11.99. FAB-MS: m/z 743
(M+).
1
2
Reaction of [Cp2(CO)3Mo2(µ-η3-P h 2P C(H)SP 2S)] (3) with
tBu Li a n d HBF 4. A solution of 3 (250 mg, 0.34 mmol) in THF
t
(50 mL) was cooled to -78 °C, and a 1.7 M solution of BuLi
(0.2 mL, 1.1 equiv) was added over 10 min, during which time
the color changed to deep orange. To the resulting mixture
was added a slight deficiency of 85% HBF4‚OEt2 (55 mg, 0.85
1
1
ν(CÃ) 1956.8 (vs), 1891.6 (s), 1862.3 cm-1 (s, sh). H NMR: δ
equiv), and the solution was stirred for /2 h at -78 °C, during
3
which time the color changed from orange to green. The
resulting solution was filtered through a pad of silica and
solvent removed in vacuo to yield green-brown [Cp2(CO)3Mo2(µ-
η3-Ph2PC(H)SP2S)] (3) as the sole product (208 mg, 83%).
Reaction of [Cp2(CO)3Mo2(µ-η3-P h 2P C(H)SP 2S)] (3) with
F e2(CO)9. To a solution of 3 (208 mg, 0.285 mmol) in THF (50
mL) was added Fe2(CO)9 (excess), and the mixture was stirred
at room temperature for 16 h. The solvent was removed under
7.64-7.37 (m, 10H, Ph), 5.09 (s, 5H, Cp), 4.65 (d, J P-H ) 2
Hz, 5H, Cp), 3.59 (s, 3H, OCH3), 2.86-2.44 (m, 2H, Ph2CH2),
2.17-2.06 (m, 2H, PCH2CH2). 31P{1H} NMR: δ 49.87 (s, P,
MoPPh2), -32.05 (d, 1J P-P ) 477 Hz, µ-η2-P2), -40.72 (d, 1J P-P
) 477 Hz, µ-η2-P2), 13C NMR: δ 232.29 (CO), 223.81 (CO),
3
216.54 (CO), 172.74 (d, J P-C ) 1.3 Hz, C(dO)OMe), 135-
127.80 (m, Ph), 87.93 (s, Cp), 83.98 (s, Cp), 60.42 (s, OCH3),
1
2
31.02 (d, J P-C ) 30 Hz, Ph2PCH2CH2), 15.05 (d, J P-C ) 9