A Simple Procedure to Ditertiary Phosphinocarboxylic Acids and Their Bisphosphine Oxides

Abstract A simple two-step route to a series of carboxylic acid functionalized ditertiary phosphine oxides is described, including the X-ray crystal structures of three representative examples namely {Ph2P(O)CH2}2N(CH2)nCO2H (n = 3−5). Strong intermolecular O−H···O H-bonding is observed in all cases leading to distinct packing arrangements.