Chemoselective Catalytic Oxidation of 1,2-Diols to α-Hydroxy Acids Controlled by TEMPO-ClO2 Charge-Transfer Complex

Org Lett. 2015 May 1;17(9):2282-5. doi: 10.1021/acs.orglett.5b01003. Epub 2015 Apr 17.

Abstract

Chemoselective catalytic oxidation from 1,2-diols to α-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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcohols / chemistry*
  • Catalysis
  • Cyclic N-Oxides / chemistry*
  • Hydroxy Acids / chemistry*
  • Oxidation-Reduction

Substances

  • Alcohols
  • Cyclic N-Oxides
  • Hydroxy Acids
  • TEMPO