N-Heterocyclic Carbene-Catalyzed Activation of Esters of N-Hydroxyphthalimide: A Highly Enantioselective Route to Chiral Dihydropyridinones Bearing an All Carbon Quaternary Stereogenic Center
Zhiming Zhang, Xiaofei Zeng*, Danbo Xie, Dongdong Chen, Liyuan Ding, Anna Wang, Limin Yang* and Guofu Zhong*
*College of Materials, Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 310036, China, Email: chemzxfhznu.edu.cn, myanghznu.edu.cn, zgfhznu.edu.cn
Z. Zhang, X. Zeng, D. Xie, D. Chen, L. Ding, A. Wang, L. Yang, G. Zhong, Org. Lett., 2015, 17, 5052-5055.
An N-heterocyclic carbene catalyzes a highly enantioselective [3 + 3] annulation reaction of N-hydroxyphthalimide (NHPI) 3,3-disubstituted acrylates and N-Ts ketimines, providing the desired chiral dihydropyridinone products bearing an all carbon quaternary stereogenic center in good yields with excellent enantioselectivities. The reaction demonstrates that NHPI acrylates are excellent substrates in NHC-catalysis.
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