Reagent for high yield, low racemization peptide coupling: Tetrahedron Lett., 1219 (1975). Mild and efficient reagent for the preparation of esters from carboxylic acids and alcohols: Tetrahedron Lett., 36, 4253 (1995); for esterification of amino acids at low temperatures, see: Tetrahedron Lett., 35, 5603 (1994); for use in formation of mixed phosphonate diesters, see: J. Org. Chem., 60, 5214 (1995). The carboxyphosphonium salts formed by reaction with carboxylic acids can be reduced with NaBH4, providng a mild method for reduction of acids to alcohols: Tetrahedron lett., 39, 3319 (1998). Promotes the reaction of aliphatic primary amines with CS2 to give isothiocyanates which can be isolated in high yield or reacted in situ with nucleophiles: J. Chem. Soc., Chem. Commun., 1995 (1995).