Alkene insertion enables ring-opening of vinyl epoxides: a theoretical perspective

Abstract

Ring-opening of vinyl epoxides is an important reaction for organic synthesis and can involve various potential mechanisms. When using a transition metal complex with both π-activity and Lewis acidity as the catalyst, the transformation modes become complicated. This mechanistic study on the Cu-catalyzed ring-opening of vinyl epoxides serves as a typical case study from a theoretical perspective. The results indicate that the ring-opening is enabled by alkene insertion, in which copper exhibits the π-activity property. The alkene insertion process plays a key role in directing the reaction pathway and determining the chemoselectivity of the overall reaction. The reaction pathways involving initial 1,3-epoxide insertion and 1,5-vinyl epoxide insertion are less energetically favorable than that triggered by alkene insertion. The atomic charges on the copper centers in each case were computed to reveal the insertion process and origins of the energy differences.