Heterocycles from Trifluoromethanesulfonamide: Formation and Structure

Sulfonamides are capable of condensing with different carbonyl compounds to form heterocycles. Among other sulfonamides, trifluoromethanesulfonamide is of special interest because of its highest NH-acidity though until recently nothing has been known of its condensation with carbonyl compounds. The focus of the present review is made on reactions of oxymethylation and amidomethylation of sulfonamides and, especially, trifluoromethanesulfonamide, the structure and stereodynamic behavior of the heterocycles formed as well as on specific and often unique stereoelectronic interactions in their molecules.