Asymmetric Epoxidation of Unsaturated Ketones Catalyzed by Heterobimetallic Rare Earth-Lithium Complexes Bearing Phenoxy-Functionalized Chiral Diphenylprolinolate Ligand

作者：Qian, Qinqin; Tan, Yufang; Zhao, Bei^*; Feng, Tao; Shen, Qi; Yao, Yingming

来源：Organic Letters, 2014, 16(17): 4516-4519.

DOI：10.1021/ol5020398

• HIGHLY ENANTIOSELECTIVE EPOXIDATION
• ALPHA,BETA-UNSATURATED CARBONYL-COMPOUNDS
• ACTINIDES ANNUAL SURVEY
• LANTHANIDE COMPLEXES
• STEREOSELECTIVE EPOXIDATION
• EPSILON-CAPROLACTONE
• HYDROGEN-PEROXIDE
• SYNTHETIC ENZYMES
• POLYAMINO-ACIDS
• ENONES

Four novel heterobimetallic complexes [REL2]{[THF)(3)Li](2)(mu-Cl)} stabilized by chiral phenoxy-functionalized prolinolate (RE = Yb (1), Y (2), Sm (3), Nd (4), H2L = (S)-2,4-di-tert-butyl-6-[[2-(hydroxydiphenylmethyl)pyrrolidin-1-yl]methyl]phenol have been synthesized and characterized. These readily available complexes are highly active in catalyzing the epoxidation of alpha,beta-unsaturated ketones, while the enantioselectivity varies according to the ionic radii of the rare earth center. A series of chalcone derivatives were converted to chiral epoxides in 80 -> 99% ee at 0 degrees C using TBHP as the oxidant in the presence of 10 mol % of 1.

• 出版日期2014-9-5
• 单位苏州大学