Silyl alkylidyne complex

A departure from these generalisations is provided by the reaction with ethynyltrimethylsilane, which yields an // -vinyl complex Tp W / -C(SiMe3) = CH2 (C0)2 in addition to the alkylidyne eomplex Tp W( = CCH2SiMe3)(CO)2 in a 45 37 ratio, consistent with eompeting 1,2- and 2,1-insertion pathways. The vinyl eomplex, however, slowly undergoes 1,2-silyl migration (> 5 days) to generate the alkylidyne complex. 

Mayr has reported a convenient synthetic approach to the large-scale preparation of thermally stable aryl and alkyl methylidyne complexes of group 6 metals based on the abstraction of oxide from suitable metal carbonyl acylates [12]. This approach has been extended to provide alkylidyne complexes bearing alkynyl [13], ferrocene-diyl [14], cymantrenyl [15] and silyl [16] substituents (Scheme 3). 

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