Synthesis of alpha-Olefins from Seed Oils

Natural seed oils are an attractive alternative to petroleum based feed stocks due to their low costs, worldwide availability, built-in functionality and renewable supply. The seed oil biorefinery concept has come to fruition with the use of the Grubbs ruthenium olefin metathesis catalyst. Ruthenium olefin metathesis has enabled the conversion of oleochemicals into pharmaceutical intermediates, antimicrobials agents, insect pheromones, waxes, cosmetics, epoxy thermoplastics, thermosets, polyolefin monomers and surfactants.

Early work with traditional ill-defined Mo, W and Re-based metathesis catalysts revealed their incompatibility with the natural seed oil’s functional groups; thereby, severely limiting commercialization efforts. Since the invention of highly active and functional group tolerant ruthenium olefin metathesis catalysts, cross metathesis of seed oils with ethylene (i.e. ethenolysis) has received special attention as this process produces alpha-olefins. However the best ethenolysis turnover number for the synthesis of methyl 9-decenoate has been 35,000. Cross metathesis of seed oils with an alpha-olefin of three carbons or higher (i.e. alkenolysis) has produced methyl 9-decenoate with turn over numbers of 200,000. This talk will describe our alkenolysis results and discuss the alkenolysis mechanism.