The conversion of seed oil based feedstocks such as methyl oleate into useful commercial raw materials via olefin metathesis has been a research focus for decades, due to their low cost and renewable supply, but technical success has been limited due to poor catalyst activities and turnovers. We report here recent studies on the cross-metathesis of methyl oleate with ethylene (ethenolysis) catalyzed by bis(tricyclohexylphosphine)benzylideneruthenium dichloride (1). At 25 °C/60 psig of ethylene, catalysis by 1 results in the highly selective formation of 1-decene and methyl 9-decenoate. However, reactivity losses limit the catalyst turnovers well below commercial viability in batch reactor operation. In an attempt to address the limitations of this chemistry, a combination of an experimental evaluation of the impact of process parameters, a detailed analysis of the fundamental reaction steps, kinetic modeling, and molecular modeling has been applied to develop a more detailed understanding of this complex catalytic pathway. These fundamental studies have led to a more complete understanding of the factors impacting catalyst performance and the identification of approaches necessary to achieve an economically viable process.

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The gas-phase irradiation of CpRh(CO)(2) (Cp = eta(5)-C(5)H(5)) was examined in order to study the rates of reaction of the 16-electron intermediates presumed to be involved in the C-H oxidative addition of alkanes. "Naked" (unsolvated) CpRh(CO) was detected, and direct measurements of the rates of reaction of this very short-lived complex with alkane C-H bonds were made. Activation of C-H bonds occurs on almost every collision for alkanes of moderate size, and intermediates in which the alkanes are bound to the metal centers, without their C-H bonds being fully broken, are implicated as intermediates in the overall reaction.

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