Enantioselective Synthesis of H‑Phosphinic Acids Bearing Natural Amino Acid Residues

The first systematic study on the asymmetric synthesis of H-phosphinic acids bearing natural protein amino acid residues was reported on the basis of the asymmetric addition of ethyl diethoxymethylphosphinate to N-tert-butanesulfinyl imines. Good yields and moderate to high enantioselectivities were obtained. Reliable methods were developed for the elucidation of the stereochemistry of these phosphinic acids and derivatives thereof. The transformation of the side chains of these analogues was studied. Methods for the conversion of the α-aminophosphinates to oligopetides were reported.