Efficiently Constructing Tetrahydroquinolines through Cascade Radical Additions and Cyclizations under the Catalysis of CuI

Abstract

AbstractAn efficient method has been developed for the construction of tetrahydroquinolines from N,N‐dimethylanilines and electron‐deficient alkenes based on CuCl/O2. A wide scope of substrates could be well tolerated, and excellent yields of the products were obtained. A series of control experiments and kinetic isotope effect experiments have been performed to gain insight of the catalytic reaction pathway. The reaction is probably initiated by the reaction of CuI and molecular oxygen to give copper(II) superoxide (CuIIOO.) as the key reactive intermediate. The formed CuIIOO. species can directly abstract a hydrogen from the α‐site of nitrogen to give the α‐amino radical intermediate, which then finishes the transformation via radical addition and cyclization.