Olefin Metathesis: Development of an Efficient Method for Alkenoylsis of Methyloleate

As the price of oil fluctuates each year depending on production, current world trade and political situations, and because of the carbon footprint left in the atmosphere by the refining of fossil fuels, there is a need to look for alternative sources of raw materials. Energy sources derived from renewable biomass products such as vegetable oils are attractive in this area. Modern catalytic processes can also be used to develop new materials, green alternatives to traditional petrochemical products, based on vegetable oils. Currently, cross-metathesis is being widely studied in the processes for processing renewable feedstocks into valuable oleochemicals, allowing the production of commercially valuable decen-1-ene and methyl esters of decenoic acid. The cross-metathesis reaction with ethylene (alkenolysis) using selective catalysts is a commercially promising way to produce "bio"decene-1 - environmentally and economically favourable compared to the traditional method of its production. The aim of the present work is to develop an efficient catalytic system for the cross-metathesis of plant raw materials based on the original Grubbs catalysts developed by us and to study the correlations between the catalytic properties of the obtained compounds and their structure for the possible implementation of the developed technology in industrial processes. In the present work, a new one-pot approach to high performance metathesis catalysts has been developed, which allows scaling up and subsequent use in the industrial production of decene-1, higher olefins and decenoic acid methyl ester from FAME (a mixture of fatty acid methyl esters). A series of new ruthenium-carbene complexes based on cyclic alkylaminocarbene ligands were synthesised and their structures determined by 1H, 13C NMR spectroscopy and X-ray diffraction analysis. An original procedure for the preparation of aldehydes by reductive hydroformylation of indene and 1,2-dihydronaphthalene derivatives on rhodium catalyst was developed. Catalytic tests were carried out with catalysts 5a-5h under different temperature conditions. Catalyst 5h proved to be the best performing catalyst for the cross-metathesis of FAME with ethylene, showing TON 215805 and a selectivity of 98% at a loading of 2 ppm.