Highly Diastereoselective Radical Cyclopropanation of Olefins via Cobaloxime‐Based Metalloradical Catalysis

Abstract Metalloradical catalysis (MRC), predominantly exemplified by metalloporphyrin complexes, has emerged as a promising strategy for regulating radical reactions and broadening their synthetic applications. In this paper, we report that cobaloxime complexes, functioning as a surrogate for metalloporphyrin systems, can mediate radical cyclopropanation of olefins using donor/acceptor‐type carbene precursor α‐aryl diazoacetates through the MRC process. The reaction proceeds under mild conditions, yielding cyclopropane derivatives in good yields with high diastereoselectivity. The reaction exhibits extensive substrate tolerance, encompassing gram‐scale transformations and the synthesis of pharmaceutical compounds. Our discoveries underscore the potential of cobaloxime‐catalyzed cyclopropanation as a valuable asset in organic syntheses and further expand the repertoire of metalloradical systems in catalysis.