A 5 + 1 Protic Acid Assisted Aza-Pummerer Approach for Synthesis of 4-Chloropiperidines from Homoallylic Amines
Rene Ebule, Sagar Mudshinge, Michael H. Nantz, Mark S. Mashuta, Gerald B. Hammond*, Bo Xu*
*University of Louisville, Louisville, Kentucky 40292, United States; Donghua University, 2999 North Renmin Lu, Shanghai 201620, China, Email: gb.hammondlouisville.edu, bo.xudhu.edu.cn
R. Ebule, S. Mudshinge, M. H. Nantz, M. S. Mashuta, G. B. Hammond, B. Xu, J. Org. Chem., 2019, 84, 3249-3259.
DOI: 10.1021/acs.joc.8b03162 (free Supporting Information)
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HCl·DMPU induces the formation of (thiomethyl)methyl carbenium ion from DMSO under mild conditions. A subsequent reaction of this electrophile with homoallylic amines generates 4-chloropiperidines in good yields. The method applies to both aromatic and aliphatic amines. The reaction has a broad substrate scope and offers good chemical yields with high functional group tolerance and scalability.
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