Chemoselective Catalytic Oxidation of 1,2-Diols to α-Hydroxy Acids Controlled by TEMPO–ClO<sub>2</sub> Charge-Transfer Complex
作者:Keisuke Furukawa、Masatoshi Shibuya、Yoshihiko Yamamoto
DOI:10.1021/acs.orglett.5b01003
日期:2015.5.1
Chemoselective catalytic oxidation from 1,2-diols to a-hydroxy acids in a cat. TEMPO/cat. NaOCl/NaClO2 system has been achieved. The use of a two-phase condition consisting of hydrophobic toluene and water suppresses the concomitant oxidative cleavage. A study of the mechanism suggests that the observed selectivity is derived from the precise solubility: control of diols and hydroxy acids as well as the active species Of TEMPO, Although the oxoammonium species TEMPO+Cl- is hydrophilic, the active species dissolves into the organic layer by the formation of the charge-transfer (CT) complex TEMPO-ClO2 under the reaction conditions.