Abstract
This review describes the development of a new class of chiral secondary phosphine oxide preligands: Amino acid-derived P-chiral diaminophosphine oxides, DIAPHOXs, and their application to several transition metal-catalyzed asymmetric reactions. The Pd-DIAPHOX catalyst system was successfully applied to enantioselective construction of quaternary stereocenters through Pd-catalyzed asymmetric allylic alkylation with β-keto esters as prochiral nucleophiles, asymmetric allylic substitutions with nitromethane, asymmetric allylic amination with various substrates, and enantioselective synthesis of axially chiral allenes. Ir-catalyzed asymmetric allylic amination and alkylation of terminal allylic carbonates were also examined using structurally optimized DIAPHOX preligands, and the corresponding branched products were obtained in a highly regio- and enantioselective manner. Furthermore, the developed processes were successfully applied to the enantioselective synthesis of biologically active compounds.
