1.8 Copper-Catalyzed Aerobic Oxidation of Alcohols

Abstract

AbstractThe oxidation of alcohols to carbonyl compounds is one of the most important reactions in organic synthesis. Owing to current environmental concerns, catalytic alcohol oxidation using molecular oxygen as the terminal oxidant has been actively investigated. Copper is frequently used as an aerobic oxidation catalyst in organic syntheses, as well as in biological systems. Co-catalysts acting in coordination with copper to promote the aerobic oxidation of alcohols have been extensively investigated, and in this context the use of nitroxyl radicals has been identified as a promising strategy. Through the efforts of many researchers, nitroxyl radical/copper catalyst systems that efficiently oxidize traditionally more challenging aliphatic alcohols under mild conditions have recently been discovered. Methods for the synthesis of esters, imines, nitriles, amides, and imides by nitroxyl radical/copper-catalyzed aerobic alcohol oxidation in the presence of other alcohols, amines, and amides have also been developed. Nitroxyl radical/copper-catalyzed aerobic alcohol oxidation exhibits outstanding chemoselectivity, and efficiently converts alcohols bearing oxidation-prone functional groups that cannot be efficiently oxidized using conventional methods.