Synthesis, characterization and olefin metathesis studies of a family of ruthenium phosphonium alkylidene complexes

The synthesis of four ruthenium phosphonium alkylidene complexes [(H2IMes)Cl2RuCH(PCy3)]+[A]− (1, A = B(C6F5)4; 2, A = BF4; 3, A = OTf; 4, A = BPh4), differing only in the anion is described. The X-ray structures of 1, 3 and 4 show them to be isostructural in the cation, with no interaction between the Ru centers and the anion. Ring closing metathesis of a substrate to a six-membered methylcyclohexene at 0 °C in CD2Cl2 using 1 mol% catalyst, shows that catalysts 1–4 behave very similarly, and exhibit superior activity in comparison to Grubbs second generation and fast-initiating catalysts.

This report details the synthesis and characterization of a family of ruthenium phosphonium alkylidene complexes of the type [(H2IMes)Cl2RuCH(PCy3)][X] (X = B(C6F5)4 (1), BF4 (2), OTf (3) or BPhu4 (4)fs). The catalytic activities of the complexes in ring-closing metathesis applications have also been studied.Figure optionsDownload as PowerPoint slide