Syntheses and Properties of Phosphinoselenoic Chlorides, Acids, and Their Salts

The synthetic methods for phosphinoselenoic chlorides, acids, and alkali metal and ammonium salts are overviewed. The addition of elemental selenium to trivalent chlorophosphines readily took place to give phosphinoselenoic chlorides. P-Chiral chlorides were efficiently prepared by the one-pot reaction of dichlorophenylphosphine or phosphorus trichloride with elemental selenium and Grignard reagents. The amination of the chlorides with optically active amines led to optically active phosphinoselenoic amides, which were applied to asymmetric synthesis as optically active ligands. The reaction of the chlorides with carbon nucleophiles occurred both at the phosphorus and selenium atoms, and the selectivity depended on the carbon nucleophiles used and the substituents at the phosphorus atom of the chlorides. The chlorides were used as key precursors leading to a variety of phosphinoselenoic, -selenothioic, -diselenoic acids and their alkali metal and ammonium salts. Finally, the stereochemical outcome at the phosphorus atom in the synthesis and substitution reaction of optically active P-chiral phosphinoselenoic chlorides is shown.