Electrochemically generated catalyst system with increased specificity and efficiency for olefin metathesis

Abstract

A facile route for the electrochemical generation of an olefin metathesis catalyst from methylene chloride solution of WCl6 was described. It was found that reductive, oxidative and pulse electrolysis produced the same intermediate. This electrolysis intermediate incorporates olefin into its structure possibly forming a metal-olefin complex, which decomposes into catalytically active metal carbene type species. ESCA, NMR and ESR methods were used to elucidate the structure of the catalyst system. The catalyst was applied in the metathesis of 1-octene and 2-octene without any need for a co-catalyst. Highly specific products with high yields were obtained. © 2003 Elsevier B.V. All rights reserved

Electro-Induced Early Transition Metal Metathesis Catalyst Systems for the Production of Polyacetylene

“…The mechanism proposed in the WCl 6 -e À -Al- CH 2 Cl 2 catalyst system involves the initial formation of the olefin adduct with the WCl 5 þ species. 23 The observed higher cis fraction of the polymer obtained with WCl 6 -e À -Al-CH 2 Cl 2 catalyst system conforms to the suggested mechanism that the olefin entering the cage around tungsten (VI) prefers the cis orientation, leading to cis double bonds in the polymer. Figure 2 illustrates the FT-IR spectra of PA prepared by MoCl 5 and WCl 6 .…”

“…21,22 We previously reported many scientific studies on the application of WCl 6 -e À -Al-CH 2 Cl 2 catalyst system to olefin metathesis reactions [23][24][25][26][27][28][29] but only one study on MoCl 5 -e À -Al-CH 2 Cl 2 catalyst system to ROMP of norbornene. 30 In this paper we described the synthesis of ROMP of COT with the electrochemically generated W and Mo-based catalyst.…”

Ring‐opening metathesis polymerization of cyclododecene using an electrochemically reduced tungsten‐based catalyst

“…In the 13 C NMR Materials, Nanoscience and Catalysis spectrum, all peaks of the polymer are in the same position as those observed previously. 14 The peak positions for the 13 C NMR spectrum of polydodecenamer are given in Table 2. The olefinic region (129-131 ppm) clearly confirms the formation of polymers by metathesis (Fig.…”

“…6). In the olefinic region of the 13 C NMR spectra of the polydodecenamer, two groups of peaks can be observed. The peaks at 130.76 and 130.30 ppm correspond to the trans and cis peaks respectively.…”

Synthesis and characterization of polyoctenamer with WCl6e−AlCH2Cl2 catalyst system via ring‐opening metathesis polymerization

“…14, 15 Here, we present a detailed study on the ROMP of a typical low-strain olefin, cyclooctene, by electrochemically generated active species. Characterization of the polyoctenamer is also investigated and discussed.…”