Copper-Promoted 6-endo-trig Cyclization of β,γ-Unsaturated Hydrazones for the Synthesis of 1,6-Dihydropyridazines
Yong-Qiang Guo, Mi-Na Zhao, Zhi-Hui Ren and Zheng-Hui Guan*
*Key Laboratory of Synthetic and Nature Molecule Chemistry of Ministry of Education, Department of Chemistry & Materials Science, Northwest University, Xi'an 710127, P. R. China, Email: guanzhhnwu.edu.cn
Y.-Q. Guo, M.-N. Zhao, Z.-H. Ren, Z.-H. Guan, Org. Lett., 2018, 20, 3337-3340.
DOI: 10.1021/acs.orglett.8b01240 (free Supporting Information)
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A copper-promoted 6-endo-trig cyclization of readily available β,γ-unsaturated hydrazones enables an efficient synthesis of a series of 1,6-dihydropyridazines with good yields, high functional group tolerance, and remarkable regioselectivity under mild conditions. Importantly, the 1,6-dihydropyridazines can be efficiently converted to biologically important pyridazines in the presence of NaOH.
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