I2-Mediated Oxidative C-N Bond Formation for Metal-Free One-Pot Synthesis of Di-, Tri-, and Tetrasubstituted Pyrazoles from α,β-Unsaturated Aldehydes/Ketones and Hydrazines
Xinting Zhang, Jinfeng Kang, Pengfei Niu, Jie Wu, Wenquan Yu* and Junbiao Chang*
*College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou, Henan Province 450001, China, Email: changjunbiaozzu.edu.cn, wenquan_yuzzu.edu.cn
X. Zhang, J. Kang, P. Niu, J. Wu, W. Yu, J. Chang, J. Org. Chem., 2014, 79, 10170-10178.
DOI: 10.1021/jo501844x (free Supporting Information)
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An I2-mediated metal-free oxidative C-N bond formation enables a regioselective pyrazole synthesis. This practical and eco-friendly one-pot protocol provides a facile access to various di-, tri-, and tetrasubstituted (aryl, alkyl, and/or vinyl) pyrazoles from readily available α,β-unsaturated aldehydes/ketones and hydrazine salts without isolation of the less stable intermediates hydrazones.
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