Catalytic asymmetric construction of C-4 alkenyl substituted pyrazolone derivatives bearing multiple stereoelements
Wande Zhang1, Shiqiang Wei1, Wenyao Wang1
1State Key Laboratory of Fine Chemicals, Department of Pharmaceutical Sciences, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, People's Republic of China. bmwang@dlut.edu.cn.
Abstract:
An organocatalytic asymmetric process was reported for the sterically precise construction of C-4 alkenyl substituted pyrazolone derivatives bearing multiple stereoelements. A series of interesting products featuring the union of a centrally chiral pyrazolone moiety and an axially chiral styrene unit were obtained in high yield with excellent diastereoselectivity and enantioselectivity (up to 99% ee, >20 : 1 dr). The process has the characteristics of mild reaction conditions, simple operation and broad substrate scope. The result of gram-scale reaction indicates that the reaction has good practicability.
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