A Highly Practical Copper(II)/TEMPO‐SO₄H Catalyst System for Aerobic Oxidations of Primary Benzylic and Allylic Alcohols on Gram‐Scale in Water

Abstract

Abstract We report a highly practical copper(II)/TEMPO‐SO 4 H catalyst system for aerobic oxidations of primary benzylic and allylic alcohols. A higher activity was achieved when TEMPO‐SO 4 H, an economically feasible 2,2,6,6‐tetramethylpiperidinyl‐1‐oxyl (TEMPO) derivative containing a sulfonic acid group, was used to replace TEMPO. The use of such Cu II /TEMPO‐SO 4 H catalysts can significantly simplify the removal of catalysts and dramatically reduce the amount of organic solvents used. The aerobic oxidation of primary benzylic and allylic alcohols was conducted in water on gram scale using air as the oxidant, and in the absence of surfactant, leading to green catalysis.