有機ニトロキシルラジカルの酸化還元特性を利用した効率的酸化システムの開発　—第一級アルコールからカルボン酸への酸化反応—

抄録

One-pot oxidation from primary alcohols to carboxylic acids is one of the most important methods in organic synthesis. With attention to the mechanistic advantage of Merck’s method (cat.2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO)/cat.NaOCl/NaClO₂), we have developed an efficient one-pot oxidation using 1-Me-AZADO⁺X^-(oxoammonium salt of 1-methyl-2-azaadamantane N-oxyl) and NaClO₂. After that, our research interest was focused on selective oxidation from diols to hydroxy acids. Herein, we report development of a highly active oxidation catalyst for selective oxidation of primary alcohols, 1,5-dimethyl-Nor-AZADO (DMN-AZADO), and DMN-AZADO-catalyzed selective oxidation of diols to hydroxy acids, and also report the chemoselective oxidation of 1,2-diols to α-hydroxy acids together with the one-pot oxidative cleavage from 1,2-diols to one-carbon-shorter carboxylic acids. A mechanistic study suggests that the formation of charge-transfer complex TEMPO-ClO₂ is a key for the observed chemoselectivity.