Mechanistic studies on Cu(NO3)2/TEMPO-catalyzed aerobic oxidation of alcohols to carboxylic acids

Abstract

Oxidation of alcohols to carbonyl compounds is one of the most important and fundamental reactions in organic chemistry. Such aerobic reactions that provide aldehydes or ketones mediated by copper and nitroxyl have been well developed during the past several decades. Recently, we successfully realized the aerobic oxidation of primary alcohols to carboxylic acids catalyzed by Cu/TEMPO for the first time. Herein, a mechanism involving a Cu(NO₃)₂–TEMPO adduct as identified by SAESI-MS studies is proposed, which is supported by our experimental studies and density functional theory (DFT) calculations.