Nano Fe3O4 catalyzed selective, tandem, and oxidative conversion of alcohols, tetrahydropyranyl and trimethylsilyl ethers to oximes

Abstract

Tandem and efficient conversion of alcohols, tetrahydropyranyl (THP) and trimethylsilyl (TMS) ethers as protected alcohols to oximes is described using a catalytic amount of nano Fe₃O₄ as a highly magnetic and nontoxic catalyst, tert-butyl hydroperoxide (TBHP) and hydroxylamine hydrochloride. The nanocatalyst is easily separated from the reaction medium using an external magnet and can be reused for several times without any considerable loss of its catalytic power. Also, it was found that it is possible to perform these oxidative conversions efficiently even in the presence of epoxides, carboxylic acids and esters, phenols, sulfides and pyridine rings with excellent chemoselectivity. The tandem and catalytic nature, catalyst reusability, high yields, and easy work up can be considered as the main advantages of the present environmentally friendly method.