Hydrosilylation of BB triple bonds: catalyst- and reductant-free construction of B-Si bonds and B 2 Si heterocycles.

Hydrosilanes undergo mild, uncatalyzed single and double 1,2-addition across the B-B triple bonds of diborynes, leading to an unsymmetrical silyldiborene and compounds with novel non-cluster three-membered B 2 Si rings. The reactions are a new addition to the very few catalyst- and alkali-metal-free methods available for the construction of B-Si bonds.