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 different nucleophilic compounds, including allylic organometallic compounds, sulfur stabilised anions, acetylides, lithiated heteroaromatic compounds etc. In addition, silylated nucleophiles are now routinely used under Mukaiyama conditions to give useful mild approaches to functionalized isoxazolidines. Attention has been also paid to the development of stereocontrolled processes; 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 synthesise enantiomerically enriched amines after cleavage of the auxiliary group and reduction of the N-O bond. Very few attempts have been reported on reactions based on chiral catalysts. So far asymmetric catalysis has not found proper applications and the opportunities offered by nitrones will represent a major challenge in this field.

nitrones - nucleophilic addition - Grignard reagents - silylated nucleophiles - allylic organometallic reagents - N,N-disubstituted hydroxylamines - stereocontrolled additions