9264
T. Shibata et al. / Tetrahedron 56 (2000) 9259±9267
(d, J7.8 Hz, 2H), 2.69 (s, 1H), 4.91±5.01 (m, 2H), 5.85
(ddt, Jd10.0, 17.4 Hz, Jt7.8 Hz, 1H), 7.34±7.44 (m, 6H),
7.64±7.67 (m, 4H); 13C NMR d21.7, 85.0, 97.3, 115.5,
128.0, 130.0, 132.6, 132.9, 134.8; HRMS found m/z
248.1015, calcd for C17H16Si: 248.1021.
(m, 5H), 0.66±0.86 (m, 2H), 0.90±1.01 (m, 2H),1.64±1.77
(m, 4H), 7.30±7.46 (m, 18H), 7.56±7.66(m, 12H); 13C
NMR d13.3, 13.6, 22.3, 23.0, 25.6, 32.2, 32.3, 33.1,
117.5, 127.6, 128.0, 129.3, 129.8, 133.9, 134.7, 136.1,
136.2, 145.3, 152.6, 186.8, 207.2; HRMS found m/z
708.3237, calcd for C49H48OSi2: 708.3244.
Typical experimental procedure for intermolecular
carbonylative coupling (Table 2, Entry 1)
2,5-Bis(allyldiphenylsilyl)-3,4-dibutylcyclopenta-2,4-dien-
1-one (2d). Yellow oil. IR (neat) 1682, 1627, 1546, 1427,
1107 cm21; lmax (MeOH) 406 nm (e 307) 1H NMR d0.54
(t, J7.0 Hz, 6H), 0.68±0.80 (m, 4H), 0.90±1.00 (m, 4H),
1.74±1.79 (m, 4H), 2.32 (d, J8.0 Hz, 4H), 4.77±4.86 (m,
4H), 5.79 (ddt, Jd10.1, 17.0 Hz, Jt8.0 Hz, 2H), 7.24±
7.35 (m, 12H), 7.44±7.47 (m, 8H); 13C NMR d13.5,
21.7, 22.9, 27.9, 32.3, 114.6, 124.3, 127.7, 129.4, 134.5,
134.9, 135.6, 177.3, 210.2; HRMS found m/z 636.3244,
calcd for C43H48OSi2: 636.3244.
A toluene solution (2 ml) of 1d (107.0 mg, 0.35 mmol) and
the corresponding dicobalt carbonyl complex of 1d
(68.2 mg, 0.12 mmol) in a 30 ml round-bottomed ¯ask
with re¯ux condenser was immersed in a hot oil bath
(1208C). The reaction mixture was stirred for 2 h, then the
resulting precipitates were removed by ®ltration through a
small pad of silica gel using a mixed eluent of hexane and
ethyl acetate (5/1,v/v). After the solvent was removed under
reduced pressure, puri®cation of the residue by thin-layer
chromatography (TLC) of silica gel afforded products in
99% yield (2d: 63.4 mg, 0.10 mmol, 86%, 3d: 9.4 mg,
0.015 mmol, 13%).
2,4-Bis(allyldiphenylsilyl)-3,5-dibutylcyclopenta-2,4-dien-
1-one (3d). Orange oil. IR (neat) 1693, 1627, 1589, 1427,
1107 cm21; 1H NMR d0.20±0.26 (m, 5H), 0.57±0.73 (m,
5H), 0.92±1.20 (m, 4H), 1.73±1.79 (m, 2H),1.93±1.98 (m,
2H), 2.32±2.40 (m, 4H), 4.82±5.00 (m, 4H), 5.75±5.91 (m,
2H), 7.29±7.58 (m, 20H); HRMS found m/z 636.3248, calcd
for C43H48OSi2: 636.3244.
2,5-Bis(diphenylmethylsilyl)-3,4-dibutylcyclopenta-2,4-
dien-1-one (2a). Yellow oil. IR (neat) 1682, 1550, 1427,
1111 cm21; lmax (MeOH) 408 nm (e 907); 1H NMR
d0.65 (t, J7.0 Hz, 6H), 0.77 (s, 6H), 0.78±0.94 (m,
4H), 1.01±1.11 (m, 4H), 1.90±1.95 (m, 4H), 7.30±7.40
(m, 12H), 7.48±7.51 (m, 8H); 13C NMR d22.4, 13.6,
23.0, 27.9, 32.4, 125.2, 127.7, 129.2, 135.0, 136.6, 176.3,
210.1; HRMS found m/z 584.2938, calcd for C39H44OSi2:
584.2931.
2,5-Bis(allylmethylphenylsilyl)-3,4-dibutylcyclopenta-
2,4-dien-1-one (2e). Yellow oil. IR (neat) 1682, 1631, 1550,
1427, 1111 cm21
;
1H NMR d0.50 (s, 6H), 0.75 (t,
J6.9 Hz, 6H), 1.04±1.25 (m, 8H), 1.98±2.18 (m, 8H),
4.81±4.94 (m, 4H), 5.66±5.82 (m, 2H), 7.27±7.39 (m,
6H), 7.48±7.56(m, 4H); HRMS found m/z 512.2927, calcd
for C33H44OSi2: 512.2932.
2,4-Bis(diphenylmethylsilyl)-3,5-dibutylcyclopenta-2,4-
dien-1-one (3a). Orange oil. IR (neat) 1693, 1589, 1427,
1107 cm21; 1H NMR d0.36±0.39 (m, 5H), 0.64±0.80 (m,
11H), 0.82±1.11 (m, 4H), 1.83±1.90 (m, 4H), 7.29±7.40
(m, 12H), 7.48±7.55 (m, 8H); 13C NMR d22.3, 21.0,
13.5, 13.7, 22.6, 23.1, 25.4, 31.6, 32.5, 32.8, 118.3, 127.7,
128.0, 129.1, 129.6, 134.9, 135.0, 135.9, 136.7, 146.0,
151.2, 184.7, 207.7; HRMS found m/z 584.2927, calcd for
C39H44OSi2: 584.2931.
2-(Allylmethylphenylsilyl)-3,4-dibutyl-5-{methylphenyl-
(1-propenyl)silyl}cyclopenta-2,4-dien-1-one. It can not
be completely puri®ed. Yellow oil. IR (neat) 1682, 1620,
1
1550, 1427, 1111 cm21; H NMR d0.49 (s, 3H), 0.55 (s,
3H), 0.734±0.81 (m, 6H), 1.02±1.25 (m, 8H), 1.87 (dd,
J1.3, 5.9 Hz, 3H), 2.00±2.17 (m, 6H), 4.79±4.89 (m,
2H), 5.66±5.81 (m, 1H), 5.97 (dd, J1.3, 18.4 Hz, 1H),
6.07±6.19 (m, 1H),7.31±7.40 (m, 6H), 7.49±7.61 (m,
4H); HRMS found m/z 512.2930, calcd for C33H44OSi2:
512.2932.
2,5-Bis(t-butyldiphenylsilyl)-3,4-dibutylcyclopenta-2,4-
dien-1-one (2b). Yellow oil. IR (neat) 1685, 1538, 1427,
1105 cm21; lmax (MeOH) 410 nm (e 893) 1H NMR d0.55
(t, J6.6 Hz, 6H), 0.64±0.76 (m, 4H), 0.85±0.96 (m, 4H),
1.18 (s, 18H), 1.62±1.67 (m, 4H), 7.30±7.42 (m, 12H),
7.57±7.60 (m, 8H); HRMS found m/z 668.3885, calcd for
C45H56OSi2: 668.3870.
2,5-Bis(diphenylvinylsilyl)-3,4-dibutylcyclopenta-2,4-dien-
1-one (2g). Yellow oil. IR (neat) 1685, 1589, 1547, 1427,
1111 cm21; 1H NMR d0.69 (t, J7.1 Hz, 6H), 0.89±1.20
(m, 8H), 2.00±2.05 (m, 4H), 5.71 (dd, J3.6, 20.3 Hz, 2H),
6.21 (dd, J3.6, 14.5 Hz, 2H), 6.43 (dd, J14.5, 20.3 Hz,
2H), 7.31±7.53 (m, 20H); HRMS found m/z 608.2919, calcd
for C41H44OSi2: 608.2931.
2,5-Bis(triphenylsilyl)-3,4-dibutylcyclopenta-2,4-dien-1-
one (2c). Yellow solid. Mp. 2018C. IR (neat) 1685, 1550,
1
1427, 1107 cm21; lmax (MeOH) 406 nm (e 765) H NMR
2,4-Bis(diphenylvinylsilyl)-3,5-dibutylcyclopenta-2,4-dien-
1-one (3g). Yellow oil. IR (neat) 1693, 1589, 1543, 1427,
d0.64 (t, J6.8 Hz, 6H), 0.75±0.87 (m, 4H), 1.06±1.17
(m, 4H), 1.85±1.90 (m, 4H), 7.30±7.42 (m, 18H), 7.54±
7.57 (m, 12H); 13C NMR d13.6, 23.0, 27.6, 32.9, 124.4,
127.7, 129.3, 134.6, 136.3, 178.2, 210.4; HRMS found m/z
708.3234, calcd for C49H48OSi2: 708.3244.
1107 cm21
;
1H NMR d0.25±0.41 (m, 5H), 0.63 (t,
J7.1 Hz, 3H), 0.69±0.79 (m, 2H), 0.83±0.95 (m, 2H),
0.98±1.08 (m, 2H), 1.89±1.94 (m, 4H), 5.67 (dd, J3.5,
20.1 Hz, 1H), 5.78 (dd, J3.5, 20.1 Hz, 1H), 6.18 (dd,
J3.5, 14.5 Hz, 1H), 6.23 (dd, J3.5, 14.5 Hz, 1H), 6.58
(dd, J14.5, 20.1 Hz, 2H), 6.72 (dd, J14.5, 20.1 Hz, 2H),
7.28±7.64 (m, 20H); HRMS found m/z 608.2932, calcd for
C41H44OSi2: 608.2931.
2,4-Bis(triphenylsilyl)-3,5-dibutylcyclopenta-2,4-dien-1-
one (3c). Orange solid. Mp. 1728C. IR (neat) 1693, 1585,
1
1427, 1107 cm21; lmax (MeOH) 426 nm (e 437) H NMR
d20.21±0.11 (m, 2H), 0.12 (t, J7.1 Hz, 3H), 0.47±0.58