Tetraarylphosphonium Salts as Soluble Supports for Oxidative Catalysts and Reagents

摘要

Tetraarylphosphonium (TAP)-supported DMSO, TEMPO, and DIB reagents were synthesized andused for the oxidation of alcohols, including Swern oxidation and for the a-acetoxylation of ketones.By taking advantage of the predictable solubility properties of the TAP unit, simple precipitation andfiltration of the phosphonium moiety permit complete separation of the desired oxidation products.This paper describes the preparation of these three TAP-supported oxidative reagents and theiractivity in the aforementioned oxidative transformations. Furthermore, we have demonstrated thatthese reagents can be recycled directly when used in catalytic processes and following regenerationwhen used in stoichiometric processes.