Synthesis of α-Quaternary Formimides and Aldehydes through Umpolung Asymmetric Copper Catalysis with Isocyanides
Kentaro Hojoh, Hirohisa Ohmiya* and Masaya Sawamura*
*Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan, Email: ohmiyap.kanazawa-u.ac.jp, sawamurasci.hokudai.ac.jp
K. Hojoh, H. Ohmiya, M. Sawamura, J. Am. Chem. Soc., 2017, 139, 2184-2187.
DOI: 10.1021/jacs.6b12881 (free Supporting Information)
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A highly regio- and enantioselective copper-catalyzed three-component coupling of isocyanides, hydrosilanes, and γ,γ-disubstituted allylic phosphates/chlorides provides chiral α-quaternary formimides in the presence of a chiral naphthol-carbene ligand and LiOtBu as base. The formimides can readily be converted to α-quaternary aldehydes.
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proposed reaction pathways