Chemoselective Reactions of Isocyanates with Secondary Amides: One-Pot Construction of 2,3-Dialkyl-Substituted Quinazolinones
Yi Lin, Shu-Fan He, Hui Geng, Yu-Chen Xiao, Kan-Lei Ji, Jian-Feng Zheng* and Pei-Qiang Huang*
*Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, P. R. China, Email: zjf485xmu.edu.cn, pqhuangxmu.edu.cn
Y. Lin, S.-F. He, H. Geng, Y.-C. Xiao, K.-L. Ji, J.-F. Zheng, P.-Q. Huang, J. Org. Chem., 2021, 86, 5345-5353.
DOI: 10.1021/acs.joc.0c02929 (free Supporting Information)
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A facile and mild method for the preparation of 2,3-dialkyl-substituted quinazolinones from readily available N-arylamides and commercial isocyanates involves a chemoselective activation of the secondary amide with Tf2O/2-Br-Pyr, addition of isocyanate, and cyclization. This reaction is general for a wide range of substrates and can be run on a gram scale.
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reaction of an amide bearing a N-2,6-dimethylaryl group with unecpected 1,2-shift of a methyl group