Unveiling the abnormal effect of temperature on enantioselectivity in the palladium-mediated decabonylative alkylation of MBH acetate

Abstract

An unusual temperature–enantioselectivity relationship was observed in the newly developed palladium-catalysed enantioselective nucleophilic substitution of cyclic Morita–Baylis–Hillman acetate and 4,4,4-trifluoro-1-phenyl-1,3-butanedione. In this transformation, higher enantioselectivity was achieved at an abnormally high temperature (140 °C) in less than 5 min. Comprehensive experimental and computational studies disclose that temperature-dependent changes in the rate-determining steps might be responsible for the abnormal effect of temperature on stereocontrol in this process.