NbCl3-Catalyzed Intermolecular [2+2+2] Cycloaddition of Alkynes and α,ω-Dienes: Highly Chemo- and Regioselective Formation of 5-(ω-Alkenyl-1,4-substituted-1,3-cyclohexadiene Derivatives

Intermolecular [2+2+2] cycloaddition of tert-butylacetylene with alpha,omega-dienes was successfully achieved by NbCl3(DME) catalyst to afford 5-omega-alkenyl-1,4-disubstituted-1,3-cyclohexadienes in excellent yields with high chemo- and regioselectivity.