B ₂ pin ₂ -Mediated Cascade Cyclization of 2-Alkenylanilines To Give 2-Difluoromethylthio/seleno-4-Aryl(alkyl)-Quinolines

Herein, we describe a B₂pin₂-mediated protocol for the synthesis of 2-difluoromethylthio/seleno-4-substituted quinolines via the cyclization of 2-alkenylanilines with TMSCF₃ and elemental sulfur or selenium. This method employs inexpensive and easy-to-handle TMSCF₃ as a dual C₁ and CF₂ source for the efficient construction of highly functionalized quinolines. The reliability, practicality, and scalability of this process are fully demonstrated through gram-scale synthesis, late-stage functionalization, and evaluation of its potential antitumor activity.