Ruthenium-catalyzed [2Â +Â 2+Â 2] cycloaddition of three different alkynes

A chemoselective [2 + 2 + 2] cycloaddition of an internal alkyne, a terminal alkyne and dimethyl acetylenedicarboxylate was efficiently catalyzed by Cp*RuCl(cod) to give trisubstituted o-phthalates in good yield.