Low-valent Niobium-mediated Synthesis of Indenes: Intramolecular Coupling Reaction of CF3 Group with Alkene C–H Bond
CF3 group of o-alkenyl-α,α,α-trifluorotoluenes underwent intramolecular coupling reaction with the alkene C–H bond under NbCl5/LiAlH4 system. Substituted indenes were obtained in good yields.