The effectiveness of ruthenium(II) complexes and ruthenium trichloride as pre-catalysts in solvent-free isomerization of model alkyl allyl ether

The isomerization of readily available allyl ethers catalyzed by soluble ruthenium complexes is an extremely versatile methodology for synthesis of O-1-propenyl systems—attractive monomers in cationic UV-radiation curing technology. From the process development perspective, the effectiveness of selected simple ruthenium catalyst precursors, mainly [RuClH(CO)(PPh3)3], [RuCl2(PPh3)3] and RuCl3·xH2O in the solvent-free isomerization of 1,4-bisallyloxybutane has been examined. The relationship between basic reaction parameters such as the reaction temperature, the amount of catalyst precursor, the promoters of non-hydride complexes (bases or alcohols), the ambient gas atmosphere and the reaction time allowing to achieve quantitative conversion of the model bisallyl ether to its 1-propenyl derivatives (τ100%) has been presented. Particular attention has been paid to the use of lower loadings of [Ru] complex required for the completion of the reaction within the reasonable times. For the first time a detailed study on the effect of the presence and amount of allyl hydroperoxides on the course of isomerization has been done.

Graphical abstractThe solvent-free isomerization of model alkyl allyl ether catalyzed by soluble ruthenium(II) complexes and ruthenium trichloride was investigated. The effectiveness of selected pre-catalysts (such as [RuClH(CO)(PPh3)3] [RuCl2(PPh3)3] and RuCl3) was examined in detail. The best results with high TOF (20,000/h) were obtained with [RuClH(CO)(PPh3)3] without any catalyst promoters.Figure optionsDownload full-size imageDownload high-quality image (60 K)Download as PowerPoint slide