Hoveyda–Grubbs type metathesis catalyst immobilized on mesoporous molecular sieves—The influence of pore size on the catalyst activity

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

“…The sample 7 holder was placed inside a dome with CaF 2 windows. The DRIFT spectra were collected in Ar (60 ml/ min).…”

“…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].…”

Opportunities of Immobilized Homogeneous Metathesis Complexes as Prominent Heterogeneous Catalysts

“…Shinde et al. immobilized a HG type catalyst functionalized with a dimethylaminosulphonyl group (Zhan catalyst; Figure , complex 33 ) on SBA‐15, MCM‐41, and MCM‐48, thereby observing an increasing reaction rate with pore size in different reactions . Solodenko et al.…”

“…In general, mesoporous supports are preferred over microporous silica (e.g. zeolites), as the latter catalysts are more prone to ruthenium leaching, whereas OMS are favored over amorphous silica ,,. The type of OMS often has a minor effect on the reaction rate of the supported complex in the metathesis of small substrates (e.g.…”

“…The type of OMS often has a minor effect on the reaction rate of the supported complex in the metathesis of small substrates (e.g. RCM of 1,7‐octadiene), but more pronounced differences in activity were observed in reactions with bulkier substrates or substrates leading to large products (Figure ): examples are reported for RCM of N , N ‐diallyl‐2,2,2‐trifluoroacetamide and tert ‐butyl‐ N , N ‐diallylcarbamate, RCM of diallyltosylamine, CM of methyl oleate, RCM of β‐citronellene, SM of 1‐decene, and for ROMP of cis ‐cyclooctene ,. Although different authors observed other orders of activity ranking between the different OMS materials, there is a general agreement that larger pore sizes lead to a higher catalytic activity.…”