Abstract Intramolecular aza-Wittig ring closures were applied to synthesize thiazolines, oxazolines, and imidazolines from β-azido thioester, ester, and amide precursors. The cyclization precursors were obtained from amino acid derivatives. Optimized conditions for diazo transfer with a fast rate and racemization suppression,(thio) esterification, and amide coupling reactions are described. The ring closure reaction can be executed with PPh 3 ...
