Mechanistic studies on the hydrosilylation of an acetylene cobalt complex; trapping an active catalyst Co2(CO)6 causing olefin-isomerization and O-silylation

We have recently reported a hydrosilylation reaction of acetylene cobalt complexes to produce the corresponding vinylsilanes. It has become clear that olefin-isomerization and O-silylation occurred under some hydrosilylation conditions. To avoid these side reactions, we found that hydrosilylation should be carried out in the presence of bis(trimethylsilyl)acetylene. The Co2(CO)6, which would cause side reactions, migrates to bis(trimethylsilyl)acetylene to form an acetylene cobalt complex. Mechanisms of olefin-isomerization and O-silylation are also discussed.