An Environmentally Benign TEMPO-Catalyzed Efficient Alcohol Oxidation System with a Recyclable Hypervalent lodine(III) Reagent and Its Facile Preparation

摘要

A highly efficient 2,2,6,6-tetramethylpiperidin-1-yloxy (TEMPO) catalyzed alcohol oxidation system using recyclable 1-chloro-l,2-benziodoxol-3(1H)-one as the terminal oxidant in ethyl acetate, which is an environmentally friend organic solvent, at room temperature has been developed. A variety of alcohols can be oxidized to their corresponding carbonyl compounds in high to excellent yields. Various heteroaromatic rings and C=C bonds are well tolerated under the reaction conditions. 1-Chloro-1,2-benziodoxol-3(1H)-one can be easily recycled after simple solid/liquid-phase separation and the subsequent regeneration sequence. In addition, a safe, very convenient, large-scale, and high-yielding procedure for the preparation of l-chloro-l,2-benziodoxol-3(1H)-one from 2-iodobenzoic acid has been developed using sodium chlorite as the stoichiometric oxidant in dilute hydrochloric acid at room temperature.