Synthesis 2019; 51(16): 3142-3150
DOI: 10.1055/s-0037-1611520
paper
© Georg Thieme Verlag Stuttgart · New York

Lithium Chloride Catalyzed Aza-Michael Addition of Pyrazoles to α,β-Unsaturated Imides

Hongyan Zhou*
a   College of Science, Gansu Agricultural University, Lanzhou 730070, P. R. of China   Email: zhouhy@gsau.edu.cn
b   College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, P. R. of China   Email: yangjy@nwnu.edu.cn
,
Xiancheng Xiang
b   College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, P. R. of China   Email: yangjy@nwnu.edu.cn
,
Ben Ma
b   College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, P. R. of China   Email: yangjy@nwnu.edu.cn
,
Ganggang Wang
b   College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, P. R. of China   Email: yangjy@nwnu.edu.cn
,
Zhixia Zhang
a   College of Science, Gansu Agricultural University, Lanzhou 730070, P. R. of China   Email: zhouhy@gsau.edu.cn
,
b   College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, P. R. of China   Email: yangjy@nwnu.edu.cn
› Author Affiliations
This work was supported by the National Natural Science Foundation of China (21362034), the Special Funds for Discipline Construction of Gansu Agricultural University (GAU-XKJS-2018-133), and the Program for Improving Scientific Research Ability of Young Teachers of Northwest Normal University (NWNU-LKQN-17-3).
Further Information

Publication History

Received: 23 January 2019

Accepted after revision: 01 April 2019

Publication Date:
17 April 2019 (online)


Abstract

A lithium chloride catalyzed aza-Michael reaction of pyrazoles to α,β-unsaturated imides has been developed. A range of aromatic and aliphatic α,β-unsaturated imides are found to be suitable for the established method, providing the corresponding aza-Michael adducts in up to 93% yields. The inexpensive catalyst, good substrate tolerance, and ease of scale-up make this procedure highly practical.

Supporting Information