The synthesis of α‐amino‐substituted diphenylphosphine oxides

Abstract Four methods with differing but overlapping specificity are described for the synthesis of α‐unsubstituted as well as α‐substituted (aminomethyl)diphenylphosphine oxides. The first method is based on the Arbusov reaction, the second on a Mannich‐type condensation of diphenylphosphine oxide [Ph2P(O)H] with aldehydes and secondary amines, the third on the addition of Ph2P(O)H to enamines and the fourth on the reaction of anions derived from α‐unsubstituted (aminomethyl)diphenylphosphine oxides with various electrophiles.