Copper(II)‐Mediated Intermolecular Radical [3+2]‐Annulation of N,N‐Dimethyl Enaminones: Direct Access to 5‐Acyl‐3‐Furancarboxaldehydes

Abstract Copper(II)‐mediated unprecedented intermolecular radical [3+2] annulation of N , N ‐dimethyl enaminones has been developed. The protocol is promoted simply by copper(II) chloride to access 5‐acyl‐3‐furancarboxaldehydes with acceptable to good yields and broad substrate scope. This reaction allows the formation of multiple new bonds, including C( sp 2 )−O bond between two nucleophilic sites, C( sp 2 )−C( sp 2 ) bond and C=O bond, through a radical cyclization process. Moreover, gram‐synthesis and application research show the potential application value of this transformation in industry. magnified image