The Future of Ethenolysis in Biobased Chemistry

Abstract

The desire to utilise biobased feedstocks and develop more sustainable chemistry poses new challenges in catalysis. A synthetically useful catalytic conversion is ethenolysis, a cross metathesis reaction with ethylene. In this Review, the state of the art of ethenolysis in biobased chemistry was extensively examined using methyl oleate as a model compound for fatty acids. Allied to this, the ethenolysis of fatty acid, polymers and more challenging substrates are reviewed. To determine the limiting factors for the application of ethenolysis on biomass, the influence of reaction parameters were investigated and the bottlenecks for reaching high turnover numbers identified.

Preparation of Musk‐Smelling Macrocyclic Lactones from Biomass: Looking for the Optimal Substrate Combination

“…[11] In the next experiment (entry 4) the addition of TFQ was tested and an increaseofthe RCM selectivity was observed. As expected, [24,25] in more concentrated solutiona ni ncreased production of the oligomeric products was observed. Finally,d ifferentd iene concentrations (3 and 7.5 mm)w ere used.…”

“…Macrocyclization by RCM, even if run in rather high dilution, [27] is always accompanied by an oligomerization process leadingt ot he formation of macromolecular dimers, trimers, and highero ligomers formedt hrough the acyclicd iene metathesis (ADMET)/ring-opening metathesis polymerization (ROMP) process. [24,25] To maximize formationo ft he expected macrocyclic monomeric product, several approaches canb e employed, such as ap ortionwise addition of the catalysts or using al arger amount of the solvent in order to run the reaction in higher dilution (> 5mm). [55] These conditions were provent ow ork for simple dienes with terminal double bonds.…”

“…[19][20][21] Although in industrial plants (sometimes called biorefineries)i nG resik In-donesia,i nS abah Malesia,o ri nP orto Marghera Italy only the alkenolysis process is utilized (usually butenolysis), ethylene is potentially much more interesting, as it can produce ah igher fractionof9-DA (9-decenoic acid) which is commercially desirable. [22][23][24][25] The latter reaction is more useful as it resultsi na more valuable product containing at erminal C-C double bond and fewer byproducts, although form any years there had been al ack of effective catalysts resistantt oe thylene, moisture, and polar contaminants present in the substrates. Recently,h owever,t he first really effective catalysts have appeared, the application of which in ethenolysis makes it possible to obtainh igh turnover numbers(TONs).…”

Direct and Tandem Routes for the Copolymerization of Ethylene with Polar Functionalized Internal Olefins

“…This aspect promoted us to explore at andem route for the incorporation of challenging polarfunctionalized internal olefins and the generation of highmolecular-weight copolymers.M etathesis-based ethenolysis has become ap owerful and versatile tool for converting internal olefins into terminal olefins. [47,48] Thus,atandem process combining ethylene-assisted ethenolysis of internal olefins and ethylene-assisted copolymerization of the preformed terminal olefins is fascinating. First, no reaction was observed between the Hoveyda-Grubbs second-generation catalyst (Ru-1)a nd the PO-Pd catalyst (see Figure S2).…”

Recent Advancements in Stereoselective Olefin Metathesis Using Ruthenium Catalysts

“…However, any CM is in equilibrium with the back reaction, ethenolysis, which is the cleavage of an internal olefin to generate two terminal olefins. Furthermore, ethenolysis of internal olefins has received attention as a method to access materials and fuels from renewable sources such as seed oil derivatives [50][51][52][53][54][55]. It was postulated that 6 could be employed in a Z-selective ethenolysis as a method to purify E-olefins.…”