5960 J. Am. Chem. Soc., Vol. 121, No. 25, 1999
Baumgartner et al.
5
(d, J(P,C) ) 1.1 Hz, p-CMe3), 34.4 (s, o-CCH3), 31.3 (s, p-CCH3),
11.4 Hz, PCSi2), 40.4 (s, o-CMe3), 35.4 (s, p-CMe3), 34.8 (s, o-CCH3),
31.3 (s, p-CCH3), 4.8 (d, J(F,C) ) 6.1 Hz, SiCH3), 6.5 (br, SiC3).
3
4.3 (d, J(P,C) ) 4.2 Hz, SiC3), 3.9 (dd, J ) 4.9 Hz, 6.5 Hz, SiC3).
MS (70 eV): m/z (relative intensity) 500 (1) [M+], 485 (3) [M+
Me], 564 (2) [M+ - Cl], 73 (100) [SiMe3+].
-
29Si{1H} NMR (THF, -90 °C): δ ) -8.4 (d, J(P,Si) ) 10.3 Hz),
2
2
-13.0 (d, J(P,Si) ) 7.9 Hz).
2
General Procedure for the Preparation of Carbenoids 10-13.
One millimole of the appropriate bisylene phosphorane (6-9) was
dissolved in 3 mL of THF. After the mixture was cooled to -78 °C,
0.7 mL of n-BuLi in n-pentane (c ) 1.6 mol L-1) was added via syringe.
31P and 6Li NMR spectroscopic assay confirmed the formation of
mixtures of the stereoisomeric carbenoids 10/15, 11/16, 12 (no
stereoisomer assigned with certainty), 13/17 in approximately 6:1 molar
ratios. The major products 10-13 were characterized in these solutions
by multinuclear NMR spectroscopy. The solutions were concentrated
in vacuo and left for crystallization at -25 °C. Compounds 10-13
were isolated as yellow or orange crystals.
Compound 13. 31P{1H} NMR (THF, -90 °C): δ ) 84.1 (t, J(P,
6
2
6Li) ) 9.0 Hz). Li{1H} NMR (THF, -90 °C): δ ) 0.6 (d, J(P,6Li)
1
4
) 9 Hz). H NMR (THF, -90 °C): δ ) 7.33 (d, 2 H, J(P,H) ) 1.2
Hz, P-aryl-H), 6.99 (s, 1 H, N-aryl-H), 6.81 (s, 1 H, N-aryl-H); o-and
p-tBu concealed by solvent signals. 13C{1H} NMR (THF, -90 °C): δ
) 148.4 (dt, 1J(P,C) ) 93.8 Hz, J(C,6Li) ) 13.8 Hz, PCClLi), 130.9
1
1
(d, J(P,C) ) 67.9 Hz, ipso-aryl); further signals of Mes* units could
not be assigned with certainty.
Preparation of Compound 15. A 6Li-doped sample of the carbenoid
15 was generated via Li/H exchange from 14 as reported previously20
and characterized by NMR spectroscopy without further workup. 31P-
Compound 10. 31P{1H} NMR (THF, -90 °C): δ ) 146.5 (t, 2J(P,
{1H} NMR (THF, -90 °C): δ ) 165.3 (t, J(P,6Li) ) 5.0 Hz). Li-
2
6
6Li) ) 6.3 Hz). Li{1H} NMR (THF, -90 °C): δ ) 0.4 (d, J(P,6Li)
) 6.5 Hz). 1H NMR (THF, -90 °C): δ ) 7.21 (2 H, aryl-H), 0.23 (s,
9 H, SiMe3), -0.37 (s, 9 H, SiMe3); o-and p-tBu are concealed by
solvent signals. 13C{1H} NMR (THF, -90 °C): δ ) 154.2 (dt, 1J(P,C)
) 113.8 Hz, 1J(C,6Li) ) 13.8 Hz, PCClLi), 154.1 (s, o-aryl), 149.0 (s,
{1H} NMR (THF, -90 °C): δ ) 0.6 (d, 2J(P,6Li) ) 5.0 Hz). 13C{1H}
6
2
NMR (THF, -90 °C): δ ) 165.3 (dt, J(P,C) ) 111.1 Hz, J(C,6Li)
1
1
2
) 12.0 Hz, PCClLi), 151.7 (d, J(P,C) ) 3.8 Hz, o-aryl), 149.3 (s,
1
3
p-aryl), 130.1 (d, J(P,C) ) 20.2 Hz, ipso-aryl), 123.1 (d, J(P,C) )
1
8.1 Hz, m-aryl), 38.7 (s, o-CMe3), 35.9 (s, p-CMe3), 33.5 (d, J(P,C)
1
3
p-aryl), 131.0 (d, J(P,C) ) 85.8 Hz, ipso-aryl), 122.8 (d, J(P,C) )
9.7 Hz, m-aryl), 49.3 (d, 1J(P,C) ) 11.4 Hz, PCSi2), 40.8 (s, o-CMe3),
36.1 (s, p-CMe3), 34.3 (s, o-CCH3), 33.2 (s, p-CCH3), 5.5 (br, SiC3),
4.0 (br, SiC3).
) 50.7 Hz, PCSi2), 33.2 (s o-CCH3), 30.3 (s, p-CCH3), 4.0 (br, SiC3),
3.4 (br, SiC3).
X-ray Crystallographic Studies of 10, 11, and 13. The structures
were solved by direct methods (SHELXS-97).43 The non-hydrogen
atoms were refined anisotropically on F2 (SHELXL-97).43 H atoms were
refined using a riding model. In 10 two THF groups and in 13 a THF
group and a p-tBu group are disordered. An extincion correction was
applied in 10 and 11. Further details are given in Table 1.
Compound 11. 31P{1H} NMR (THF, -90 °C): δ ) 146.6 (t, 2J(P,
6Li) ) 6.4 Hz). Li{1H} NMR (THF, -90 °C): δ ) 0.2 (d, J(P,6Li)
) 6.4 Hz). 1H NMR (THF, -90 °C): δ ) 7.21 (2 H, aryl-H), 0.23 (s,
9 H, SiMe3), -0.37 (s, 9 H, SiMe3); o-and p-tBu are concealed by
solvent signals. 13C{1H} NMR (THF, -90 °C): δ ) 154.3 (d, 2J(P,C)
6
2
1
Acknowledgment. Financial support by the Deutsche For-
schungsgemeinschaft and the Fonds der Chemischen Industrie
is gratefully acknowledged. This work is dedicated to Professor
Dr. Joachim Bargon on the occasion of his 60th birthday.
) 3.1 Hz, o-aryl), 150.5 (s, p-aryl), 147.0 (dt, J(P,C) ) 127.0 Hz,
1J(C,6Li) ) 14.5 Hz, PCBrLi), 132.5 (d, 1J(P,C) ) 83.2 Hz, ipso-aryl),
123.5 (d, 3J(P,C) ) 9.2 Hz, m-aryl), 51.5 (d, 1J(P,C) ) 6.5 Hz, PCSi2),
40.0 (s, o-CMe3), 35.5 (s, p-CMe3), 34.3 (s, o-CCH3), 31.2 (s, p-CCH3),
3
6.3 (d, J(P,C) ) 1.9 Hz, SiC3), 4.7 (br, SiC3).
Compound 12. 31P{1H} NMR (THF, -90 °C): δ ) 135.9 (dt,
Supporting Information Available: Full tables of crystal
data, final atomic coordinates, anisotropic thermal parameters,
complete positional parameters, and bond distances and angles
for 10, 11, and 13 (PDF). This material is available free of
2J(P,F) ) 36.1 Hz, J(P,6Li) ) 7.3 Hz). Li{1H} NMR (THF, -90
2
6
°C): δ ) 0.5 (d, J(P,6Li) ) 7.3 Hz). 19F{1H} NMR (THF, -90 °C):
2
2
1
δ ) -122.6 (d, J(P,F) ) 36.1 Hz). H NMR (THF, -90 °C): δ )
4
7.44 (d, 2 H, J(P,H) ) 2.6 Hz, aryl-H), 0.12 (d, 9 H, J(F,H) ) 1.2
Hz) SiCH3), -0.40 (s, 9 H, SiCH3); o-and p-tBu concealed by solvent
signals. 13C{1H} NMR (THF, -90 °C): δ ) 221.9 (ddt, J(F,C) )
1
JA990074E
370.8 Hz, 1J(P,C) ) 109.1 Hz, 1J(C,6Li) ) 14.4 Hz, PCFLi), 156.2 (s,
o-aryl), 151.0 (s, p-aryl), 127.3 (dd, 1J(P,C) ) 80.3 Hz, 3J(F,C) ) 7.0
Hz, ipso-aryl), 123.5 (d, 3J(P,C) ) 9.9 Hz, m-aryl), 49.3 (d, 1J(P,C) )
(43) (a) Sheldrick, G. M. SHELXS-97. Acta Crystallogr. 1990, A46,
467-473. (b) Sheldrick, G. M. SHELXL-97; Universita¨t Go¨ttingen,
Germany, 1997.