Asymmetric [3+2]-dipolar cycloaddition of azomethine ylides generated from Au-catalyzed intramolecular redox reaction of nitronyl alkynes

Abstract

An electronically-tuned hydroxylamine functions as an excellent chiral auxiliary for [3+2] cycloaddition of the azomethine ylides generated in-situ from gold- catalyzed redox reaction of alkynyl nitrones. a-methyl-p-nitrobenzyl auxiliary leads to an excellent level of rotameric and thus diastrereo-facial control and the resulting auxiliary could be easily removed after the cycloaddition.