On the nature of the nucleophile in the mixture of phosphites and amines

It is now commonly accepted that in the presence of strong bases (like meta l alcoholates) an equilibrium between phosphite and phosphonate forms of di alkyl phosphites exists and that the phosphite form is highly reactive in t he reaction with carbonyl compounds. There is a controversy on the structur e of the active form of the phosphite when the addition is catalyzed by ami nes. We have found that aliphatic amines and dialkyl phoshites form a compl ex which is a reactive species. Its stoichiometry depends on the nature of the solvent.