Palladium(II)-Catalyzed Distal C?H Functionalization of 8-Aminoquinolinamides: Facile Synthesis of Triarylmethane Derivatives

Abstract

Herein, a straightforward approach is reported for the palladium-catalyzed oxidative remote CH alkylation of 8-aminoquinoline derivatives using para-quinone methides. This method enables selective C5-alkylation of quinolines and exhibits a site-selectivity distinct from that typically observed in convetional palladium-catalyzed sp² CH activation. The reaction proceeds via chelation-induced remote CH functionalization, and a broad range of quinolinamides are successfully coupled with p-quinone methides, demonstrating excellent substrate scope and functional group tolerance. Preliminary mechanistic studies suggest a reversible CH metalation step as part of the catalytic cycle.