Synthetic Chemistry of Phosphoroselenoic Acid Derivatives with a Binaphthyl Group

Abstract

The first synthetic example of phosphoric acids with a binaphthyl group appeared in 1971. Since then, their use as chiral molecular tools slowly increased. In contrast, the reports in 2004 that those acids with 3,3’-disubstituted binaphthyl groups catalyzed Mannich-type asymmetric reactions dramatically facilitated the development of catalytic reactions with those acids as chiral Brønsted acids. One simple idea to design isologues of those acids was the replacement of the oxygen atom of P=O and P-O groups with heavier elements in the Periodic Table. In fact, some isologues with a P=S bond appeared, but no derivatives with a P=Se bond were seen in 2001. We then started to develop the synthetic chemistry of selenium isologues of phosphoric acid derivatives with a binaphthyl group. The accidental finding of the formation of phosphoroselenoyl chlorides with a binaphthyl group stimulated our studies, and we developed a range of the derivatives with oxygen-, nitrogen-, and carbon-containing substituents on the phosphorus atom. Some of them can be used as a chiral discriminating agent, key starting materials to optically active alcohols, diselenides, organophosphorus compounds with a chiral carbon atom adjacent to the phosphorus atom, optically active trivalent organophosphorus compounds. During our studies, we also found the reaction involving the transfer of the axial chirality of a binaphthyl group to the central chirality of the phosphorus atom.