Ring-Closing Olefin Metathesis of 2,2'-Divinylbiphenyls: A Novel and General Approach to Phenanthrenes

The ring-closing olefin metathesis (RCM) of 2,2¢-divinylbiphenyls, using a second-generation RCM ruthenium-based catalyst, leads to differently substituted phenanthrenes in quantitative yield under very mild reaction conditions, independent of both nature and position of the groups present on the biphenyl moiety.