Regioselective Hydrostannations with Mo(CO)3(CNtBu)3 (MoBI3) as a New, Efficient Catalyst

Mo(CO)3(NCtBu)3 (MoBI3) was found to be a suitable catalyst for the regioselective hydrostannation of several types of alkynes, preferentially giving rise to the α-stannylated products. These products are not available under radical reaction conditions, or by using other metal catalysts. This protocol tolerates a wide range of functional groups, and can also be applied to sensitive substrates, which cannot be hydrometallated with the commonly used palladium catalysts.