Asymmetric Epoxidation of Unsaturated Ketones Catalyzed by Heterobimetallic Rare Earth-Lithium Complexes Bearing Phenoxy-Functionalized Chiral Diphenylprolinolate Ligand
Qinqin Qian, Yufang Tan, Bei Zhao*, Tao Feng, Qi Shen and Yingming Yao*
*College of Chemistry, Chemical Engineering and Materials Science, Dushu Lake Campus, Soochow University, Suzhou 215123, China, Email: zhaobeisuda.edu.cn, yaoymsuda.edu.cn
Q. Qian, Y. Tan, B. Zhao, T. Feng, Q. Shen, Y. Yao, Org. Lett., 2014, 16, 4516-4519.
DOI: 10.1021/ol5020398 (free Supporting Information)
Heterobimetallic complexes stabilized by chiral phenoxy-functionalized prolinolate are highly active in catalyzing the epoxidation of α,β-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 good ee at 0°C using TBHP as the oxidant.
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C. Zeng, D. Yuan, B. Zhao, Y. Yao, Org. Lett., 2015, 17, 2242-2245.