CHIRAL PHOSPHINES FOR PALLADIUM-CATALYZED ASYMMETRIC ALPHA-ARYLATION OF ESTER ENOLATES TO PRODUCE TERTIARY STEREOCENTERS IN HIGH ENANTIOSELECTIVITY

摘要

The disclosure provides new and improved methods for the Pd-catalyzed asymmetric α-arylation of ester compounds, which produce the corresponding α-aryl moiety in high enantioselectivity (generally 90% ee). The present methods utilize a palladium catalyst supported by new (R)—H8-BINOL-derived monophosphine ligands. The method is applicable to a wide variety of aryl triflate substrates having variations in both electronic and steric properties. These aryl triflate substrates react with various α-alkyl (Z)- and/or (E)-0-trimethylsilyl ketene acetals in the presence of a Pd catalyst, (R)—H8-BINOL-derived monophosphine ligand, and a mild activator, for example, LiOAC, to provide the asymmetric α-arylation of ester compounds in high ee.