Copper-Catalyzed Divergent Trifluoromethylation/Cyclization of Unactivated Alkenes

Most of the precedent copper-catalyzed trifluoromethylation reactions of unactivated alkenes concern terminal alkenes, and these processes are terminated in elimination, or nucleophilic addition, or semipinacol rearrangement, or C-H bond functionalization steps. In this study, we develop a trifluoromethylation method for both unactivated terminal and internal alkenes to enable divergent late-stage radical cyclization and achieve high molecular complexity. These cyclizations are well consistent with Baldwin I s rule. Furthermore, a kinetic isotope effect (KIE) study and control reactions were conducted, and a plausible mechanism is proposed.