Enantioselective Multicomponent Electrochemical Difunctionalization of Terminal Alkynes
Qiannan Wang, Xinyu Wang, Yong Liu, Jiayin Zhang, Jin Song, Chang Guo
Abstract
The direct functionalization of alkyne triple bonds using a radical strategy provides an efficient platform for creating a wide range of substituted alkenes. However, developing a multicomponent enantioselective radical reaction using feedstock alkynes to forge all-carbon quaternary stereocenters─while addressing challenges related to compatibility, selectivity, and efficiency─remains relatively rare. Here we report an enantioselective electrochemical nickel-catalyzed three-component cross-coupling of readily available terminal alkynes, diverse racemic alkyl radical precursors, and group transfer reagents (such as (TMS) 3 Si-H, RSe-SeR, RTe-TeR, and CHI 3 ), achieving excellent regio-, stereo-, and enantioselectivities (more than 70 examples, up to 95% ee). Electricity-mediated difunctionalizations significantly expand the scope of both aliphatic and aromatic alkynes, demonstrating excellent functional group compatibility. The key to success lies in the rational design of anodically generated nickel-bound tertiary radical intermediates, which stereoselectively capture alkynes to form vinyl radicals and participate in subsequently diverse group transfer processes to enable the intermolecular and anti -stereoselective difunctionalization of alkynes. This approach allows the transformation of terminal alkynes into diverse structural entities with α-quaternary stereogenic centers.