Ruthenium Metathesis: A Key Step To Access a New Cyclic Tetrasubstituted Olefin Platform.

An rapid and mild synthetic route for the preparation of cyclic tetrasubstituted platforms via ruthenium-catalyzed ring-closing metathesis (RCM) has been developed. This process tolerates a wide range of functionalities such as nitrogen, oxygen, sulfur, silicon, and carbon tethered groups, as well as very challenging fluorine and boron atoms (36 derivatives, up to 96%). This diversity-oriented method was further demonstrated by the postfunctionalization reactions, such as Pd-couplings, N-substitution, and reductive amination introducing a morpholine moiety.