Enantioselective Synthesis of gem-Diaryl Benzofuran-3(2H)-ones via One-Pot Asymmetric Rhodium/Palladium Relay Catalysis.

An asymmetric dual-metal relay catalysis strategy that combines Rh/chiral sulfur-olefin-catalyzed enantioselective 1,2-addition with a Pd-catalyzed intramolecular C-O coupling has been developed. The method allows rapid and efficient synthesis of quaternary carbon-containing gem-diaryl benzofuran-3(2H)-ones in good yields in a highly enantioselective manner (up to 99% ee) through a simple one-pot cascade reaction.