Phosphabicyclononane-Containing Ru Complexes: Efficient Pre-Catalysts for Olefin Metathesis Reactions

The catalytic performances of three Phosphabicyclononane (Phoban)-containing ruthenium-based pre-catalysts have been evaluated for metathesis transformations. A wide screening of substrates in ring-closing metathesis reactions reveals the greater efficiency of pre-catalyst 4. Comparison of the catalytic activities of 4 with Grubbs' first-generation pre-catalyst illustrates the key role of the Phoban ligand. Additionally, a comparative study of three Phoban-containing pre-catalysts has been conducted for the self-metathesis of 1-octene at low catalyst loading (25-100 ppm).