Synthesis and acid-base properties of α-aminophosphoryl compounds

Abstract

α-Aminophosphoryl compounds of the phosphonate, phosphine oxide, and α,ω-bis(phosphine oxide) series and some of their thiophosphoryl analogs were synthesized. Potentiometric measurements of the pK a of the conjugate acids revealed an insignificant effect of variation of substituents on the phosphorus, nitrogen, and α-carbon atoms on the basicity of the phosphorylated amines. The latter are weak bases. Organophosphorus groups decrease the basicity of the amines by almost 5 pK a units. The role of the hydrophobic effect and intramolecular H-bonding in the obtained substances was discussed.