Nucleophilic additions to nitrones

In recent years increasing interest has been devoted to widen the scope of the formerly studied reaction of nitrones with Grignard reagents to differe nt nucleophilic compounds, including allylic organometallic compounds, sulf ur stabilised anions, acetylides, lithiated heteroaromatic compounds etc. I n addition, silylated nucleophiles are now routinely used under Mukaiyama c onditions to give useful mild approaches to functionalized isoxazolidines. Attention has been also paid to the development of stereocontrolled process es; nitrones derived from glyceraldehyde and congeners have been carefully studied and interesting reversions of facial selectivity have been reported by complexing them with Lewis acids. N-Glycosyl nitrones are used to synth esise enantiomerically enriched amines after cleavage of the auxiliary grou p and reduction of the N-O bond. Very few attempts: have been reported on r eactions based on chiral catalysts. So far asymmetric catalysis has not fou nd proper applications and the opportunities offered by nitrones will repre sent a major challenge in this field.