Sustainable electrochemical dehydrogenative C(sp3)–H mono/di-alkylations

Abstract

Catalyst-free, direct electrooxidative phenol derivatives C(sp³)–H mono- and di-alkylation reaction have been developed. In contrast to previous typical oxidative and electrochemical coupling, this electrosynthetic approach enables selective mono- and di-alkylations through metal- and external oxidant-free mild conditions via easily available electrodes. Advances of this strategy were proven by an unparalleled broad substrate scope for efficient C–C, C–N, C–O bond formation as well as excellent site- and regioselectivity. The electrochemical selective alkylations were devoid of additional electrolytes, could be conducted on a gram scale, and provided the enone products by cascade electrooxidative dehydrogenation, which highlight a notable potential for further late-stage diversification. Detailed mechanistic studies allowed to delineate the exact profile of the generation of the mono- and di-alkylation events.