Transition-Metal-Free Selective C-H Benzylation of Tertiary Arylamines by a Dearomatization-Aromatization Sequence

Abstract

Due to the significance of hybrid systems in drug discovery, there is an urgent need to assemble multiple biologically active ingredients into a single molecule. Here, we report a general transition-metal-free selective C-H benzylation of tertiary arylamines in good to excellent yields with a broad substrate scope and high functional-group tolerance under mild conditions. Besides arylamines, some other benzene derivatives also readily furnished the corresponding diaryl methane derivatives with this protocol. A series of control experiments and theoretical calculations indicated that this transition-metal-free reaction is a dearomatization-aromatization process.

Keywords: C−H bond functionalization; Friedel-Crafts alkylation; dearomatization-aromatization sequence; tertiary arylamine; transtion-metal free.