Nickel-Catalyzed Mono- and Dihydrosilylation of Aliphatic Alkynes in Aqueous and Aerobic Conditions

Abstract

1,1-Disilanes are synthetically versatile building blocks, owing to their low toxicity, high stability, and unique structures. However, the practical synthesis of 1,1-disilanes is still a challenge. Despite the available Fe-, Co-, La-, and B-catalyzed protocols, the use of highly reactive reductants, such as EtMgBr, NaBHEt3, or KHMDS, inevitably requires air- and moisture-free conditions. Herein, we report the homogeneous Ni-catalyzed mono- and dihydrosilylation of aliphatic terminal alkynes under either air and water conditions or neat conditions, affording beta-(E)-vinylsilanes and 1,1-disilanes in high yields with complete regioselectivity and stereoselectivity. Importantly, our method is gram-scalable and the sole example of Ni-catalyzed dihydrosilylation of alkynes. We demonstrated the introduction of different silyl groups through the stepwise addition of each silane source in a reaction vessel. Furthermore, the reaction intermediates were characterized with spectroscopic/spectrometric tools, and density functional theory calculations were performed to understand the reaction mechanism and the origins of the regioselectivity for beta-(E)-vinylsilanes and 1,1-disilanes.