Reactions of a Hydrido(hydrosilylene)ruthenium Complex with α,β-Unsaturated Ketones and Heterocumulenes

摘要

Reactivity study of silylene complexes with organic substrates would lead to the development of new transformation reactions of organosilicon compounds. An increasing number of silylene complexes have been prepared and their reactivities have been investigated, but the examples of highly reactive silylene complexes are still rare. Our group reported the synthesis of hydrido(hydrosilylene)tungsten complex, Cp~*(CO)2(H)W=Si(H) -{C(SiMe3)3} (1), as well as its new and high reactivities toward several polar unsaturated organic substrates. Especially, tungsten complex 1 reacted with α,β-unsaturated ketones to give novel η~3-siloxyallyl complexes almost quantitatively and streoselectively. We proposed a possible reaction mechanism for this reaction including a [2+4] cycloaddition process. Recently, we also succeeded in the synthesis of its ruthenium analogue Cp~*(CO)(H)Ru=Si(H){C(SiMe3)3} (2). Here, we report the reactions of complex 2 with α,β-unsaturated ketones and heterocumulenes. The reaction mechanisms are also discussed.