Hoveyda–Grubbs type metathesis catalyst immobilized on mesoporous molecular sieves MCM-41 and SBA-15

Abstract

SummaryA commercially available Hoveyda–Grubbs type catalyst (RC303 Zhannan Pharma) was immobilized on mesoporous molecular sieves MCM-41 and on SBA-15 by direct interaction with the sieve wall surface. The immobilized catalysts exhibited high activity and nearly 100% selectivity in several types of alkene metathesis reactions. Ru leaching was found to depend on the substrate and solvent used (the lowest leaching was found for ring-closing metathesis of 1,7-octadiene in cyclohexane – 0.04% of catalyst Ru content). Results of XPS, UV–vis and NMR spectroscopy showed that at least 76% of the Ru content was bound to the support surface non-covalently and could be removed from the catalyst by washing with THF.

Valorisation of vegetable oils via metathesis reactions on solid catalysts: Cross-metathesis of methyl oleate with 1-hexene

“…However,the industrial application of homogeneous olefin metathesis catalysts is hampered bythe expensive catalyst separation processes needed to obtain high-purity chemicals and the contamination of products by Ru catalyst residues that are difficult to eliminate.Therefore, increasing research efforts have been made lately for developing active and stable immobilized supported complexes that allow straightforward catalyst separation and recovery. For example, commercial available Ru-alkylidene complexes immobilized on different supports have been employed without leaching or significant activity loss for olefin metathesis reactions [5,6,7]. Recently, we reported that silicasupported HG complexesare stable, highly active and selective catalysts for the selfmetathesisof methyl oleate [8].…”

Efficient, large-scale synthesis and preclinical studies of MRS5698, a highly selective A3 adenosine receptor agonist that protects against chronic neuropathic pain

“…We presently use Zhan catalyst-1B (Hoveyda-Grubbs type catalyst) to convert 6 to 7 [24] by a ring closure metathesis reaction. This is followed subsequently by cyclopropanation using diethyl zinc in dichloromethane to form protected bicyclic intermediate 10.…”

Heterogeneous olefin‐metathesis: Comparative perspective of the activity with respect to unsaturated fatty acid methyl esters

“…The stability of the catalyst system not only depends on the type of support material and/or the immobilization technique but also on the nature of the solvent as the extent of leaching of active species varies with the solvent type . When Hoveyda‐Grubbs II catalyst (Figure ; Table ) supported on SBA‐15 molecular sieves was employed for metathesis reactions, the highest leaching was observed in dichloromethane while the least was detected in benzene solvent.…”