An approach based on combinations of various water compatible Lewis acids and lipophilic group containing amphiphilic prolinamide co-catalysts has been evaluated for the direct asymmetric Aldol reaction. From the broa...An approach based on combinations of various water compatible Lewis acids and lipophilic group containing amphiphilic prolinamide co-catalysts has been evaluated for the direct asymmetric Aldol reaction. From the broad screening of chloride salts from alkali metal to transition metal, LiC1, ZnCI2 and SnCI2 lead to the highest stereoselectivities. The optimized catalytic conditions （10 mol% prolinamide with 10 mol% MC12 or 20 mol% LiC1 at room temperature on water） gave anti-products with improved enantioselectivities （up to 99% ee） compared to the moderately stereoselective procedure based on prolinamide activation only.展开更多
An efficient direct asymmetric aldol reaction with zinc triflate and prolinamides as combined catalysts is reported.A series of chiral prolinamides have been designed and used in the direct aldol reaction resulting in...An efficient direct asymmetric aldol reaction with zinc triflate and prolinamides as combined catalysts is reported.A series of chiral prolinamides have been designed and used in the direct aldol reaction resulting in the desired products with excellent yields(up to 94% yield) and high enantioselectivities(up to 96% ee).Water was found to play a significant role in the formation of the aldol products,which suggests a new strategy in the design of new organic catalysts.展开更多
Prolinamido-glycoside catalyzed asymmetric aldol reaction in aqueous media is reported. The reactions are rapid and highly stereoselective when water is used as solvent. The stereoselectivities were under influence of...Prolinamido-glycoside catalyzed asymmetric aldol reaction in aqueous media is reported. The reactions are rapid and highly stereoselective when water is used as solvent. The stereoselectivities were under influence of configurations of a prolyl residue of the catalyst and α-chiral aldehydes. Water soluble prolinamido-glycoside catalysts are easily separable from reaction mixture and can be recycled and re-used several times.展开更多
文摘An approach based on combinations of various water compatible Lewis acids and lipophilic group containing amphiphilic prolinamide co-catalysts has been evaluated for the direct asymmetric Aldol reaction. From the broad screening of chloride salts from alkali metal to transition metal, LiC1, ZnCI2 and SnCI2 lead to the highest stereoselectivities. The optimized catalytic conditions （10 mol% prolinamide with 10 mol% MC12 or 20 mol% LiC1 at room temperature on water） gave anti-products with improved enantioselectivities （up to 99% ee） compared to the moderately stereoselective procedure based on prolinamide activation only.
基金the National Natural Science Foundation of China (20772056)Jiangsu 333 Program (for Pan) for the generous financial support+1 种基金The research funds for Pan from the Qing-Lan Program of Jiangsu Provincethe Kua-Shi-Ji Program of the Education Ministry of China
文摘An efficient direct asymmetric aldol reaction with zinc triflate and prolinamides as combined catalysts is reported.A series of chiral prolinamides have been designed and used in the direct aldol reaction resulting in the desired products with excellent yields(up to 94% yield) and high enantioselectivities(up to 96% ee).Water was found to play a significant role in the formation of the aldol products,which suggests a new strategy in the design of new organic catalysts.
文摘Prolinamido-glycoside catalyzed asymmetric aldol reaction in aqueous media is reported. The reactions are rapid and highly stereoselective when water is used as solvent. The stereoselectivities were under influence of configurations of a prolyl residue of the catalyst and α-chiral aldehydes. Water soluble prolinamido-glycoside catalysts are easily separable from reaction mixture and can be recycled and re-used several times.
