A hybrid Au/Ru catalyst for sequential alkyne hydration/asymmetric transfer hydrogenation reactions

Abstract

The utilization of organic/inorganic core/shell support materials by compartmentalizing of Au(i)/Ru(ii) catalysts has led to the formation of chiral alcohol derivatives from alkynes via sequential alkyne hydration and asymmetric transfer hydrogenation reactions. A Ru(ii) complex was supported on chiral ligand end-capped amphiphilic ROMP polymers. The micellar Ru(ii) catalyst was coated with a mesoporous silica shell to produce a secondary compartment where an IPrAuCl complex was confined in mesopores of silica gel through post-pore size reduction. A variety of alkynes were converted to chiral alcohol derivatives in quantitative yields with high enantioselectivity in a MeOH/H2O mixture using sequential alkyne hydration/asymmetric transfer hydrogenation reactions. A hybrid catalytic system was developed for sequential alkyne hydration/asymmetric transfer hydrogenation reactions through the confinement of an amphiphilic polymer supported ruthenium and gold catalysts within core/shell silica gel.