New Reactions of Stable Silylenes

Some recent chemistry of the stable silylenes, (CHNtBu)2Si: (1) and (CH2NtBu)2Si: (2) is reported [1]. The X-ray crystal structure of 1 has finally been determined. Both silylenes react with transition metal carbonyls to displace CO and form silylene complexes. Complexes of 1 and 2 with Cr, Mo, W, Fe, Ru, and Ni have been prepared and studied structurally. Reactions of 1 and 2 with halocarbons yield either simple addition of the C-X bond to the silylene, or 2:1 silylene: halocarbon products containing a Si-Si bond, depending on the halocarbon. Silylene 1 catalyzes the polymerization of nearly all compounds containing carbon-carbon double or triple bonds. Possible mechanisms are proposed for several of the reactions described above.