Bulky NHC–Cobalt Complex-Catalyzed Highly Markovnikov-Selective Hydrosilylation of Alkynes

The hydrosilylation of alkynes is one the most attractive and, at same time, challenging catalytic transformations, usually demanding use noble transition metals. We describe a system, based on cobalt(0) complex and bulky N-heterocyclic carbene (NHC) ligands, permitting highly effective broad scope silanes. application NHC ligands allowed decrease in amount cobalt necessary for an reaction run to 2.5 mol% provided excellent selectivity towards ?-vinylsilanes. developed method tolerates number substituted aryl, alkyl, silyl acetylenes. Moreover, it suitable both tertiary secondary Our findings confirm that steric hindrance around metal center can effectively increase activity catalyst ensure better than those analogous complexes bearing smaller ligands.