Highly Enantioselective Epoxidation of α,β-Unsaturated Ketones Using Amide-Based Cinchona Alkaloids as Hybrid Phase-Transfer Catalysts
Maciej Majdecki, Agata Tyszka-Gumkowska and Janusz Jurczak*
*Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland, Email: jurczak_groupicho.edu.pl
M. Majdecki, A. Tyszka-Gumkowska, J. Jurczak, Org. Lett., 2020, 22, 8687-8691.
DOI: 10.1021/acs.orglett.0c03272 (free Supporting Information)
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A series of 20 chiral epoxides were obtained with excellent yields and enantioselectivities within short reaction times using hybrid amide-based Cinchona alkaloids as catalysts at very low loading. Moreover, the catalyst solution can be reused 10times, without further catalyst addition to the reaction mixture.
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proposed transition-state model for catalyst with E-chalcone