Kinetics and Mechanism of the Oxidation of Aliphatic Alcohols by Butyltriphenylphosphonium Dichromate

Abstract

Selective oxidation of organic compounds under non-aqueous conditions is an important transformation in synthetic organic chemistry. For this, a number of different chromium (VI) derivatives have been reported.1'2 In 1997, Baltork et al3 reported a new Cr(VI) derivative - butyltriphenylphosphonium dichromate (BTPPD). BTPPD is reported to convert alcohols to corresponding carbonyl compounds in yields ranging from 80 to 100%. It oxidises amines to azo-compounds, thiols to disulphides and regenerate carbonyl compounds from their oximes. We have been interested in the kinetics and mechanisms of the oxidations by BTPPD and some reports on the oxidation by BTPPD have emanated from our labpratory.4"6 In this paper, we report the kinetics of the oxidation of some aliphatic primary and secondary alcohols by BTPPD in dimethylsulphoxide (DMSO) as the solvent. Mechanistic aspects are discussed.