Trifluoromethylthio-promoted Nazarov cyclization of α-SCF3-vinyl (hetero)aryl ketones.

A trifluoromethylthio-promoted Nazarov cyclization of α-SCF3-vinyl (hetero)aryl ketones has been developed using trifluoromethanesulfonic acid in dichloromethane. This efficient protocol affords the corresponding α-SCF3-substituted cyclopentenone-fused polycyclic products in good yields (up to 96%). The bromo-substituted polycyclic products were further utilized in Sonogashira and Suzuki cross-coupling reactions, demonstrating their synthetic versatility. Density functional theory (DFT) calculations revealed that the α-SCF3 substituent lowers the activation barrier, thereby facilitating the cyclization. This strategy provides an efficient route to a novel class of SCF3-substituted polycyclic compounds.