Integrated Process of Aerobic Oxidation-Olefination-Asymmetric C-C Bond Formation Catalyzed by Robust Heterogeneous Gold/Palladium and Chirally Modified Rhodium Nanoparticles

We have achieved an integrated process of oxidation-olefination-asymmetric 1,4-addition reactions under aerobic and aqueous conditions using metal nanoparticles as robust heterogeneous catalysts. A tandem process of aerobic oxidation and Horner-Wadsworth-Emmons olefination was successfully catalyzed by gold/palladium bimetallic nanoparticles. A wide range of substrates gave the desired products in high yields and excellent selectivities. This tandem process was further connected with an asymmetric 1,4-addition reaction catalyzed by chiral rhodium nanoparticles to achieve a challenging three-step, one-pot sequential reaction. Various types of esters with a chiral center at the beta-position were obtained from readily available and stable alcohols and arylboronic acids in high yields with high enantioselectivities in a one-pot sequential reaction integrating three transformations.