Abstract The preparation, physical and spectroscopic properties of l-amino-2- arylethylphosphonic, and-phosphinic acids as well as-phosphine oxides, the phosphorus analogues of phenylalanine are described, and the reactions of l-amino-2-(4-fluorophenyl) ethylphosphonates with acetals, isocyanides, esters, acid anhydrides, activated aromatic nitro-and halogen compounds, and with N-protected alanine are reported. It is shown that ...