Platform Chemicals from an Oilseed Biorefinery

The US chemical industry is $460 billion in size where a$150 billion segment of which is non-oxygenated chemicals that is sourced today via petroleum but is addressable by a renewable feedstock if one considers a more chemically reduced feedstock such as vegetable oils. Vegetable oil, due to its chemical functionality, provides a largely untapped opportunity as a renewable chemical source to replace petroleum-derived chemicals and produce platform chemicals unavailable today. This project examined the fertile intersection between the rich building blocks provided by vegetable oils and the enhanced chemical modification capability provided by metathesis chemistry. The technology advanced in this study is the process of ethylene cross-metathesis (referred to as ethenolysis) with vegetable oil and vegetable oil derivatives to manufacture the platform-chemical 9-decenoic acid (or 9DA) and olefin co-products. The project team meet its goals of demonstrating improved catalyst efficiencies of several multiples, deepening the mechanistic understanding of metathesis, synthesis and screening of dozens of new catalysts, designing and modeling commercial processes, and estimating production costs. One demonstrable result of the study was a step change improvement in catalyst turnover number in the ethenolysis of methyl oleate as reported here. We met our key measurable of producing 100 lbs of 9DA at the pilot-scale, which demonstrated ability to scale-up ethenolysis. DOE Project funding had significant positive impact on development of metathetically modified vegetable oils more broadly as the Cargill/Materia partnership, that was able to initiate primarily due to DOE funding, has succeeded in commercializing products, validating metathesis as a platform technology, and expanding a diverse products portfolio in high value and in large volume markets. Opportunities have expanded and business development has gained considerable momentum and enabled further expansion of the Materia/Cargill relationship. This project exceeded expectations and is having immediate impact on DOE success by replacing petroleum products with renewables in a large volume application today

Kinetic Selectivity of Olefin Metathesis Catalysts Bearing Cyclic (Alkyl)(Amino)Carbenes

The evaluation of ruthenium olefin metathesis catalysts 4–6 bearing cyclic (alkyl)(amino)carbenes (CAACs) in the cross-metathesis of cis-1,4-diacetoxy-2-butene (7) with allylbenzene (8) and the ethenolysis of methyl oleate (11) is reported. Relative to most NHC-substituted complexes, CAAC-substituted catalysts exhibit lower E/Z ratios (3:1 at 70% conversion) in the cross-metathesis of 7 and 8. Additionally, complexes 4–6 demonstrate good selectivity for the formation of terminal olefins versus internal olefins in the ethenolysis of 11. Indeed, complex 6 achieved 35 000 TONs, the highest recorded to date. CAAC-substituted complexes exhibit markedly different kinetic selectivity than most NHC-substituted complexes

Latent Ruthenium Olefin Metathesis Catalysts That Contain an N-Heterocyclic Carbene Ligand

A new N-heterocyclic carbene containing olefin metathesis catalyst, (sIMes)(Cl)_2Ru(CH(CH_2)_2-C,N-2-C_5H_4N) (4a), was synthesized from (sIMes)(PCy_3)(Cl)_2RuCHPh (1) or (sIMes)(py)_2(Cl)_2RuCHPh (3). When heated at 40 °C in dichloromethane, 4a is slowly converted to its isomer 4b. The X-ray structures of 4a and 4b show that the NHC and pyridine ligands are trans in 4a and cis in 4b. 4a is more latent than 1 and 4b much more latent than 4a in ring-closing metathesis (RCM) and ring-opening metathesis polymerization (ROMP)

Highly Efficient Ruthenium Catalysts for the Formation of Tetrasubstituted Olefins via Ring-Closing Metathesis

A series of ruthenium-based metathesis catalysts with N-heterocyclic carbene (NHC) ligands have been prepared in which the N-aryl groups have been changed from mesityl to mono-ortho-substituted phenyl (e.g., tolyl). These new catalysts offer an exceptional increase in activity for the formation of tetrasubstituted olefins via ring-closing metathesis (RCM), while maintaining high levels of activity in ring-closing metathesis (RCM) reactions that generate di- and trisubstituted olefins

Development of a Method for the Preparation of Ruthenium Indenylidene-Ether Olefin Metathesis Catalysts

The reactions between several derivatives of 1-(3,5-dimethoxyphenyl)-prop-2-yn-1-ol and different ruthenium starting materials [<em>i.e.</em>, RuCl<sub>2</sub>(PPh<sub>3</sub>)<sub>3</sub> and RuCl<sub>2</sub>(p-cymene)(L), where L is tricyclohexylphosphine di-<em>t</em>-butylmethylphosphine, dicyclohexylphenylphosphine, triisobutylphosphine, triisopropylphosphine, or tri-<em>n</em>-propylphosphine] are described. Several of these reactions allow for the easy, <em>in-situ</em> and atom-economic preparation of olefin metathesis catalysts. Organic precursor 1-(3,5-dimethoxyphenyl)-1-phenyl-prop-2-yn-1-ol led to the formation of active ruthenium indenylidene-ether complexes, while 1-(3,5-dimethoxyphenyl)-prop-2-yn-1-ol and 1-(3,5-dimethoxyphenyl)-1-methyl-prop-2-yn-1-ol did not. It was also found that a bulky and strong σ-donor phosphine ligand was required to impart good catalytic activity to the new ruthenium complexes

Development of a Method for the Preparation of Ruthenium Indenylidene-Ether Olefin Metathesis Catalysts

The reactions between several derivatives of 1-(3,5-dimethoxyphenyl)-prop-2-yn-1-ol and different ruthenium starting materials [i.e., RuCl2(PPh3)3 and RuCl2(p-cymene)(L), where L is tricyclohexylphosphine di-t-butylmethylphosphine, dicyclohexylphenylphosphine, triisobutylphosphine, triisopropylphosphine, or tri-n-propylphosphine] are described. Several of these reactions allow for the easy, in-situ and atom-economic preparation of olefin metathesis catalysts. Organic precursor 1-(3,5-dimethoxyphenyl)-1-phenyl-prop-2-yn-1-ol led to the formation of active ruthenium indenylidene-ether complexes, while 1-(3,5-dimethoxyphenyl)-prop-2-yn-1-ol and 1-(3,5-dimethoxyphenyl)-1-methyl-prop-2-yn-1-ol did not. It was also found that a bulky and strong σ-donor phosphine ligand was required to impart good catalytic activity to the new ruthenium complexes

Reactivation of a Ruthenium-Based Olefin Metathesis Catalyst

First-generation Hoveyda–Grubbs olefin metathesis catalyst was purposely decomposed in the presence of ethylene, yielding inorganic species that are inactive in the ring-closing metathesis (RCM) of the benchmark substrate diethyl diallylmalonate (DEDAM). The decomposed catalyst was treated with 1-(3,5-diisopropoxyphenyl)-1-phenylprop-2-yn-1-ol (<b>3</b>) to generate an olefin metathesis active ruthenium indenylidene-ether complex in 43% yield. This complex was also prepared independently by reacting RuCl₂(<i>p</i>-cymene)­(PCy₃) with the organic precursor <b>3</b>. The activity of the isolated reactivated catalyst in the RCM of DEDAM is similar to that of the independently prepared complex