Cobalt-Catalyzed Facial-Selective Hydroalkylation of Cyclopropenes

Abstract

Cyclopropene hydrofunctionalization has been a promising strategy for accessing multi-substituted cyclopropanes; however, cyclopropene hydroalkylation remains underdeveloped. Herein, we report a low-valent CoH-catalyzed facial-selective cyclopropene hydroalkylation to access multi-substituted cyclopropanes. This reaction exhibits a broad substrate scope of alkyl halides and cyclopropenes and tolerates many functional groups. Moderate-to-good facial-selectivity is obtained without any directing groups. Mechanism studies provide evidence that alkyl radicals are generated from alkyl halides and irreversible CoH insertion is responsible for the facial-selectivity. Our preliminary exploration demonstrates that asymmetric cyclopropene hydroalkylation can be realized without conspicuous auxiliary groups.

Keywords: CoH; Cross-Coupling; Cyclopropene; Facial-Selectivity; Hydroalkylation.