Chiral Urea-Catalyzed Enantioselective Epoxidation Of Alpha, Beta-Unsaturated Esters

A highly enantioselective epoxidation of trans-alpha-cyano-alpha, beta-unsaturated esters has been described by using cinchona alkaloid-derived urea and H2O2 as the organocatalysts and oxidant, giving chiral glycidic ester derivatives containing cyano groups in good yields (up to 95%) with excellent enantioselectivities (up to 97% ee). A plausible transition state was also proposed. (C) 2021 Elsevier Ltd. All rights reserved.