NbCl3-catalyzed intermolecular [2+2+2] cycloaddition of alkynes and alpha,omega-dienes: highly chemo- and regioselective formation of 5-omega-alkenyl-1,4-substituted-1,3-cyclohexadiene derivatives.

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