Cobalt-Catalyzed Regiodivergent Double Hydrosilylation of Arylacetylenes

Double hydrosilylation of alkynes represents a straightforward method to synthesize bis(silane)s, yet it is challenging if alpha-substituted vinylsilanes act as the intermediates. Here, a cobalt-catalyzed regiodivergent double hydrosilylation of arylacetylenes is reported for the first time involving this challenge, accessing both vicinal and geminal bis(silane)s with exclusive regioselectivity. Various novel bis(silane)s containing Si-H bonds can be easily obtained. The gram-scale reactions could be performed smoothly. Preliminarily mechanistic studies demonstrated that the reactions were initiated by cobalt-catalyzed alpha-hydrosilylation of alkynes, followed by cobalt-catalyzed beta-hydrosilylation of the alpha-vinylsilanes to deliver vicinal bis(silane)s, or hydride-catalyzed alpha-hydrosilylation to give geminal ones. Notably, these bis(silane)s can be used for the synthesis of high-refractive-index polymers (n(d) up to 1.83), demonstrating great potential utility in optical materials.

Automated summary

A cobalt-catalyzed regiodivergent double hydrosilylation reaction has been developed, enabling the synthesis of bis(silane)s with specific regioselectivity. These bis(silane)s show promising applications in optical materials.