B(C6F5)3-catalyzed TMSOTf-assisted intermolecular redox-neutral cyclization of N,N-dialkyl arylamines and allylic esters

Abstract

Herein, we present an unprecedented intermolecular redox-neutral cyclization of tertiary anilines and allylic esters to deliver a wide range of substituted tetrahydroquinolines with high efficiency. This one-pot strategy is initiated by Lewis acid-catalyzed Friedel–Crafts alkylation, followed by hydride abstraction from the α-amino C–H bond mediated by B(C₆F₅)₃, cyclization and hydride transfer to the cationic intermediate to form tetrahydroquinoline derivatives. The use of commercially available catalysts and readily available reagents, and a step-economical procedure, together with external oxidant-free conditions, make this an efficient method for tetrahydroquinoline synthesis.