Development of a Method for the Preparation of Ruthenium Indenylidene-Ether Olefin Metathesis Catalysts

Abstract

The reactions between several derivatives of 1-(3,5-dimethoxyphenyl)-prop-2-yn-1-ol and different ruthenium starting materials [<em>i.e.</em>, RuCl₂(PPh₃)₃ and RuCl₂(p-cymene)(L), where L is tricyclohexylphosphine di-<em>t</em>-butylmethylphosphine, dicyclohexylphenylphosphine, triisobutylphosphine, triisopropylphosphine, or tri-<em>n</em>-propylphosphine] are described. Several of these reactions allow for the easy, <em>in-situ</em> and atom-economic preparation of olefin metathesis catalysts. Organic precursor 1-(3,5-dimethoxyphenyl)-1-phenyl-prop-2-yn-1-ol led to the formation of active ruthenium indenylidene-ether complexes, while 1-(3,5-dimethoxyphenyl)-prop-2-yn-1-ol and 1-(3,5-dimethoxyphenyl)-1-methyl-prop-2-yn-1-ol did not. It was also found that a bulky and strong σ-donor phosphine ligand was required to impart good catalytic activity to the new ruthenium complexes.

Keywords

• olefin metathesis
• ring-closing metathesis
• ruthenium indenylidene
• ruthenium alkylidene