Abstract

Silphos [PCl3-n(SiO2)n], a heterogeneous phosphine reagent provides a facile and efficient method for the dehydration of aldoximes and Beckmann rearrangement of ketoximes in CH3CN at room temperature without occurrence of any deprotection reaction. Silphos also deprotects oximes in the presence of catalytic amounts of molecular bromine in excellent yields. The separation of the produced Silphos oxide is chromatography-free and simply by filtration.

Keywords: deprotection, Beckmann rearrangement, dehydration, amide, nitrile, ketoxime, aldoxime, Silphos