Transition-Metal-Free [3 + 2] Cycloaddition of Nitroolefins and Diazoacetonitrile: A Facile Access to Multisubstituted Cyanopyrazoles
Zhen Chen, Yue Zhang, Jing Nie and Jun-An Ma*
*Department of Chemistry, Tianjin Collaborative Innovation Center of Chemical Science & Engineering, Tianjin University, Tianjin 300072, P. R. of China, Email: majun_an68tju.edu.cn
Z. Chen, Y. Zhang, J. Nie, J.-A. Ma, Org. Lett., 2018, 20, 2024-2027.
DOI: 10.1021/acs.orglett.8b00729 (free Supporting Information)
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A transition-metal-free [3 + 2] cycloaddition reaction between diazoacetonitrile and nitroolefins provides multisubstituted cyanopyrazoles. This protocol offers mild reaction conditions, broad substrate scope, good yields, and regioselectivities. An one-pot three-component reaction of nitroolefins with diazoacetonitrile and alkyl halides also provides multisubstituted cyanopyrazoles in good to high yields.
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