Synthesis of Ru alkylidene complexes

The present work describes the robust synthesis of Ru alkylidene complexes (PCy3)2Cl2Ru=CHR – precursors for metathesis catalysts. Moreover, the dynamic behavior of complexes where R = 2-naphthyl and 2-thienyl was studied. 1H NMR techniques were employed to establish the preferred conformations in solution for both complexes and the energy barrier for rotation around single (Ru=)CH–C(thienyl) bond was estimated (ΔG ≠ 303K = 12.6 kcal/mol).