Radical Alkylation of Imines with 4-Alkyl-1,4-dihydropyridines Enabled by Photoredox/Bronsted Acid Cocatalysis

Radical alkylation of imines with 4-alkyl-1,4-dihydropyridines cocatalyzed by iridium/ruthenium complex and Bronsted acid under visible light irradiation has been achieved. Both aldimines and ketithines can undergo this transformation. Common functional groups, such as hydroxyl groups, ester, amide, ether, cyanide, and heterocycles, can be tolerated in this reaction. A variety of structurally diverse amines (57 examples) have been produced with up to 98% isolated yields using this method.