Synthesis of 4-(Bromodifluoromethylseleno) Isocoumarins via Selenolation/Lactonization of 2-Alkynylbenzoates Enabled by a Multi-Component Reagents System

Abstract

p-CF₃BnSeCF₂Br was developed as a bromodifluoromethylselenonating reagent, which was utilized by combining with mCPBA and Tf₂O for the synthesis of 4-(bromodifluoromethylseleno) isocoumarins via the selenolation/lactonization of 2-alkynylbenzoates. The transformation was postulated to proceed via a multicomponent reagents system-enabled sequence involving the oxidation of p-CF₃BnSeCF₂Br by mCPBA into its selenium sulfoxide, activation of the generated sulfoxide by Tf₂O into the electrophilic p-CF₃BnSeOCF₂Br salt, and selenolation/lactonization of 2-alkynylbenzoates by the reactive electrophilic species into 4-(bromodifluoromethylseleno) isocoumarins.