Synthesis of tetrasubstituted α-aminophosphonic acid derivatives from trisubstituted α-aminophosphonates

An efficient method for the preparation of quaternary α- aminophosphonic acid derivatives is reported. The nucleophilic addition of organometallic reagents to α-ketiminophosphonates allows the preparation of quaternary α-aminophosphonates. The diastereoselective synthesis of a quaternary α-aminophosphonate using a chiral tartaric-acid-derived phosphonate is also described. The preparation of quaternary α-aminophosphonates is described. α-Ketiminophosphonates are generated from tertiary α-aminophosphonates, and subsequent nucleophilic addition of Grignard reagents or sodium acetylide allows the preparation of tetrasubstituted α-aminophosphonates.