Rhodaelectro‐Catalyzed peri‐Selective Direct Alkenylations with Weak O‐Coordination Enabled by the Hydrogen Evolution Reaction (HER)

Abstract

Abstract Direct C−H functionalizations by electrocatalysis is dominated by strongly coordinating N(sp2)‐directing groups. In sharp contrast, direct electrocatalytic transformations of weakly‐coordinating phenols remain underdeveloped. Herein, electrooxidative peri C−H alkenylations of challenging 1‐naphthols were achieved by versatile rhodium(III) catalysis via user‐friendly constant current electrolysis. The rhodaelectrocatalysis employed readily‐available alkenes and a protic reaction medium and features ample scope, good functional group tolerance and high site‐ and stereoselectivity. The strategy was successfully applied to high‐value, nitrogen‐containing heterocycles, thereby providing direct access to uncommon heterocyclic motifs based on the dihydropyranoquinoline skeleton. A rhodium‐catalyzed electrooxidative alkenylation of oxidation‐sensitive 1‐naphthols as well as 4‐ and 5‐hydroxyquinolines has been developed. It employs readily available starting materials, and the C−C bond formation proceeds with high site‐ and stereoselectivity, with molecular H2 as the only stoichiometric waste product. image