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 Co-2(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. (C) 2002 Elsevier Science Ltd. All rights reserved.