Radical Addition of Hydrazones by α-Bromo Ketones To Prepare 1,3,5-Trisubstituted Pyrazoles via Visible Light Catalysis
Xiu-Wei Fan, Tao Lei, Chao Zhou, Qing-Yuan Meng, Bin Chen, Chen-Ho Tung and Li-Zhu Wu*
*Technical Institute of Physics and Chemistry and University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, P. R. China, Email: lzwumail.ipc.ac.cn
X.-W. Fan, T. Lei, C. Zhou, Q.-Y. Meng, B. Chen, C.-H. Tung, L-Z. Wu, J. Org. Chem., 2016, 81, 7127-7133.
DOI: 10.1021/acs.joc.6b00992 (free Supporting Information)
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Visible light catalysis enables an efficient tandem reaction of hydrazones and α-bromo ketones to provide 1,3,5-trisubstituted pyrazoles. A radical addition followed by intramolecular cyclization affords the important pyrazole skeleton in good to excellent yields under mild conditions with wide group tolerance.
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