Synthesis of Pyrrole-2-carbaldehyde Derivatives by Oxidative Annulation and Direct Csp3-H to C=O Oxidation
Xia Wu, Peng Zhao, Xiao Geng, Can Wang, Yan-dong Wu and An-xin Wu*
*Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China, Email: chwuaxmail.ccnu.edu.cn
X. Wu, P. Zhao, X. Geng, C. Wang, Y.-d. Wu, A.-x. Wu, Org. Lett., 2018, 20, 688-691.
DOI: 10.1021/acs.orglett.7b03821 (free Supporting Information)
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Pyrrole-2-carbaldehydes can efficiently be prepared from aryl methyl ketones, arylamines, and acetoacetate esters via oxidative annulation and Csp3-H to C=O oxidation in the presence of a copper catalyst, iodine, and oxygen. Mechanistic investigations indicate that the aldehyde oxygen atom originates from oxygen. The reaction avoids the use of stoichiometric quantities of hazardous oxidants.
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