Organophotoredox and Cobalt‐catalyzed 1,2‐Difunctionalization of Mono‐Donor Cyclopropanes

Selective functionalization of unactivated C─C and C─H bonds in mono‐donor cyclopropanes represents a significant yet challenging goal in organic synthesis. Although numerous reported studies have documented the 1,3‐difunctionalization of these substrates, effective strategies for 1,2‐difunctionalization have so far proven elusive. Herein, we report a novel catalytic strategy enabling the 1,2‐difunctionalization of mono‐donor cyclopropanes. By merging of organophotoredox and cobalt catalytic system, this method achieves selective ring‐opening and homobenzylic oxygenation, facilitated by a two‐fold sequence involving single electron transfer, nucleophilic addition, and acceptorless dehydrogenation. This unprecedented process overturns the predominant 1,3‐selectivity in mono‐donor cyclopropane functionalization, concurrently establishing a streamlined platform for forging β‐aryl‐α′‐oxyketone derivatives in a sustainable manner.