Comprehensive study on olefin metathesis in PEG as an alternative solvent under microwave irradiation

Polyethylene glycols (PEGs) are non-toxic, biodegradable and sustainable organic solvents, which find a large application in the chemical and pharmaceutical industry. In this study, we present the ring-closing metathesis reaction (RCM) in PEG under microwave irradiation. Several benchmark substrates, yielding 5- to 6-membered rings featuring di- or tri-substituted olefins, were evaluated. This study demonstrated that PEGs are suitable solvent for olefin metathesis. However, depending on the substrate/catalyst couple, isomerization may occur.

Graphical abstractRing-closing metathesis (RCM) was performed in PEG under microwave activation. The product was recovered by a precipitation/filtration method. In some cases, isomerization may occur.Figure optionsDownload full-size imageDownload high-quality image (102 K)Download as PowerPoint slideHighlights► PEGs were examined as alternative solvents in ring-closing metathesis. ► Various ruthenium-based catalysts were studied in this reaction. ► Microwave heating was the method of choice to activate the reaction. ► In some cases, an isomerization side reaction occurred. ► The organic product was isolated by a precipitation/filtration method.