First Transformation of Unsaturated Fatty Esters Involving Enyne Cross-Metathesis

A cooperative zinc/catalytic indium system for the stereoselective sequential synthesis of (E)-1,3-dienes from carbonyl compounds

A novel cooperative system based on zinc/catalytic indium for the stereoselective synthesis of highly functionalized (E)-1,3-dienes from aldehydes and ketones has been developed.

The Future of Ethenolysis in Biobased Chemistry

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.

Ethenolysis: A Green Catalytic Tool to Cleave Carbon-Carbon Double Bonds

Remarkable innovations have been made in the field of olefin metathesis due to the design and preparation of new catalysts. Ethenolysis, which is cross-metathesis with ethylene, represents one catalytic transformation that has been used with the purpose of cleaving internal carbon-carbon double bonds. The objectives were either the ring opening of cyclic olefins to produce dienes or the shortening of unsaturated hydrocarbon chains to degrade polymers or generate valuable shorter terminal olefins in a controlled manner. This Review summarizes several aspects of this reaction: the catalysts, their degradation in the presence of ethylene, some parameters driving their productivity, the side reactions, and the applications of ethenolysis in organic synthesis and in potential industrial applications.

Terminal conjugated dienes via a ruthenium-catalyzed cross-metathesis/elimination sequence: application to renewable resources

Two-step synthesis of terminal 1,3-dienes catalyzed by two different ruthenium complexes.

Methyl ricinoleate as platform chemical for simultaneous production of fine chemicals and polymer precursors

The modification of methyl ricinoleate by etherification of the hydroxyl group was accomplished by using a nonclassical ruthenium-catalyzed allylation reaction and also by esterification. Methyl ricinoleate derivatives were engaged in ring-closing metathesis (RCM) reactions leading to biosourced 3,6-dihydropyran and α,β-unsaturated lactone derivatives with concomitant production of polymer precursors. Sequential RCM/hydrogenation and RCM/cross-metathesis were also implemented as a straightforward method for the synthesis of tetrahydropyran and lactone derivatives as well as valuable monomers (i.e., polyamide precursors).

Ene-yne cross-metathesis with ruthenium carbene catalysts

Conjugated 1,3-dienes are important building blocks in organic and polymer chemistry. Enyne metathesis is a powerful catalytic reaction to access such structural domains. Recent advances and developments in ene–yne cross-metathesis (EYCM) leading to various compounds of interest and their intermediates, that can directly be transformed in tandem procedures, are reviewed in this article. In addition, the use of bio-resourced olefinic substrates is presented.

Improving sustainability in ene-yne cross-metathesis for transformation of unsaturated fatty esters

Ruthenium-catalyzed ene-yne cross-metathesis is performed with stoichiometric proportions of terminal olefins and alkynes. This is made possible by the continuous addition of the alkyne to the reaction mixture. The protocol allows the ene-yne cross-metathesis reaction to be carried out with long-chain terminal olefins and in a one-pot fashion with internal olefins after shortening by ethenolysis. The efficient conversion of renewable unsaturated fatty esters from bioresources into valuable conjugated 1,3-dienes of interest for further transformations is performed using this technique under mild conditions in dimethyl carbonate; an ecofriendly solvent.