Transition Metal Catalysis Involving Cleavages of #sigma#-Bonds between Group 14 Elements and Characterization of Metal Complexes Relevant to the Catalyst Intermediates

摘要

Some homogeneous transition metal catalysts are highly active to cleave #sigma#-bonds between group 14 elements under mild reaction conditions. Various unsaturated compounds insert into the #sigma#-bonds to afford a wide wariety of products having the group 14 elements. We have utilized silylstannanes (Si-Sn), disilanes (Si-Si), and distannanes (Sn-Sn) in the presence of a transition metal catalyst to realize 1,4-silylstannation of 1,3-dienes, 1,2-silylstannation of olefins, dimerization and bis-silylation of 1,3-dienes, 1,4-carbosilylation of 1,3-dienes, silylation of allylic esters, and bis-stannylation of 1,3-dienes. The structures and fluxional behavior of cis-bis(stannyl)bis(phosphine)platinum, cis-bis(silyl)bis(phosphine)platinum, and cis-bis(stannyl)bis(phosphine)palladium complexes were examined. In the fluxional process, all the spin-spin coupling are retained. The fluxionality is attributed to unimolecular twist-rotation via a pseudotetrahedral transition state.