Propylphosphonic anhydride (T3P®): An expedient reagent for organic synthesis

The present review article focuses on the recent advancements in amide and peptide coupling reactions of racemization-prone substrates using n-propylphosphonic anhydride (T3P). It summarizes its utility in the preparation of various carboxylic acid derivatives including esters, azides, hydroxamates, thiohydroxamates, carbamates, Weinreb amides, etc. Besides, its role in a variety of organic functional group transformations (e.g. conversion of aldoximes and ketoximes into nitriles and amides, oxidation of alcohols into olefins and corresponding carbonyl compounds, conversion of carboxylic acids and amides into nitriles and isonitriles, reduction of carboxylic acids into alcohols, acetalization and thioacetalization of aldehydes, conversion of Nα-protected amino/peptide acids into thioacids, etc.) and in synthesis of heterocyclic compounds is also discussed.