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Unexpected Formation of NHC-Stabilized Hydrosilylyne Complexes via Alkane Elimination from NHC-Stabilized
Tetsuya Fukuda1, Hisako Hashimoto1, Hiromi Tobita1
1Department of Chemistry, Graduate School of Science, Tohoku University , Aoba-ku, Sendai, 980-8578, Japan.
Abstract:
N-heterocyclic carbene (NHC)-stabilized hydrosilylyne complex Cp*(CO)2WSiH((Me)IMe)2 (3a) ((Me)IMe = 1,3,4,5-tetramethylimidazole-2-ylidene) was formed by the reaction of an NHC-stabilized silylene complex Cp*(CO)2(H)WSiH((Me)IMe){C(SiMe3)3} (2a) with 1 equiv of (Me)IMe at 70 °C. In this reaction, HC(SiMe3)3 was unexpectedly eliminated from 2a. A C5Me4Et analogue of 3a, (C5Me4Et)(CO)2WSiH((Me)IMe)2 (3b), was also synthesized by the same method, and the structure of 3b was confirmed by X-ray crystallography. Although the silicon center of 3b is coordinated by two NHCs, the length of the W-Si bond of 3b [2.363(4) Å] is as short as that of the shortest W═Si double bond (∼2.36 Å). These complexes, 3a and 3b, are the first examples of a base-stabilized silylyne complex having only a hydrogen on the silicon atom.
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