Reactivity of the alkene component in the ruthenium-catalyzed [2+2] cycloaddition between an alkene and an alkyne: Part 2

Ruthenium-catalyzed [2+2] cycloadditions of 2,3-disubstituted norbornadienes and 2-substituted norbornadienes with an alkyne were found to be highly chemo- and stereoselective with moderate level of regioselectivities and only small rate differences were observed with different substituents on the norbornadiene.