A comprehensive mechanistic picture of the isomerizing alkoxycarbonylation of plant oils
Type
ArticleAuthors
Roesle, PhilippCaporaso, Lucia

Schnitte, Manuel
Goldbach, Verena
Cavallo, Luigi

Mecking, Stefan
KAUST Department
Biological and Environmental Sciences and Engineering (BESE) DivisionChemical Science Program
KAUST Catalysis Center (KCC)
Physical Science and Engineering (PSE) Division
Date
2014-11-21Online Publication Date
2014-11-21Print Publication Date
2014-12-03Permanent link to this record
http://hdl.handle.net/10754/563911
Metadata
Show full item recordAbstract
Theoretical studies on the overall catalytic cycle of isomerizing alkoxycarbonylation reveal the steric congestion around the diphosphine coordinated Pd-center as decisive for selectivity and productivity. The energy profile of isomerization is flat with diphosphines of variable steric bulk, but the preference for the formation of the linear Pd-alkyl species is more pronounced with sterically demanding diphosphines. CO insertion is feasible and reversible for all Pd-alkyl species studied and only little affected by the diphosphine. The overall rate-limiting step associated with the highest energetic barrier is methanolysis of the Pd-acyl species. Considering methanolysis of the linear Pd-acyl species, whose energetic barrier is lowest within all the Pd-acyl species studied, the barrier is calculated to be lower for more congesting diphosphines. Calculations indicate that energy differences of methanolysis of the linear versus branched Pd-acyls are more pronounced for more bulky diphosphines, due to involvement of different numbers of methanol molecules in the transition state. Experimental studies under pressure reactor conditions showed a faster conversion of shorter chain olefin substrates, but virtually no effect of the double bond position within the substrate. Compared to higher olefins, ethylene carbonylation under identical conditions is much faster, likely due not just to the occurrence of reactive linear acyls exclusively but also to an intrinsically favorable insertion reactivity of the olefin. The alcoholysis reaction is slowed down for higher alcohols, evidenced by pressure reactor and NMR studies. Multiple unsaturated fatty acids were observed to form a terminal Pd-allyl species upon reaction with the catalytically active Pd-hydride species. This process and further carbonylation are slow compared to isomerizing methoxycarbonylation of monounsaturated fatty acids, but selective.Citation
Roesle, P., Caporaso, L., Schnitte, M., Goldbach, V., Cavallo, L., & Mecking, S. (2014). A Comprehensive Mechanistic Picture of the Isomerizing Alkoxycarbonylation of Plant Oils. Journal of the American Chemical Society, 136(48), 16871–16881. doi:10.1021/ja508447dSponsors
P.R. gratefully acknowledges support from the Carl-Zeiss-Foundation by a graduate fellowship. We thank Dako AG for donation of high-oleic sunflower oils.Publisher
American Chemical Society (ACS)Relations
Is Supplemented By:- [Dataset]
Roesle, P., Caporaso, L., Schnitte, M., Goldbach, V., Cavallo, L., & Mecking, S. (2015). CCDC 1010345: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc12xbs3. DOI: 10.5517/cc12xbs3 HANDLE: 10754/624344 - [Dataset]
Roesle, P., Caporaso, L., Schnitte, M., Goldbach, V., Cavallo, L., & Mecking, S. (2015). CCDC 1010346: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc12xbt4. DOI: 10.5517/cc12xbt4 HANDLE: 10754/624345 - [Dataset]
Roesle, P., Caporaso, L., Schnitte, M., Goldbach, V., Cavallo, L., & Mecking, S. (2015). CCDC 1010347: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc12xbv5. DOI: 10.5517/cc12xbv5 HANDLE: 10754/624346 - [Dataset]
Roesle, P., Caporaso, L., Schnitte, M., Goldbach, V., Cavallo, L., & Mecking, S. (2015). CCDC 1010348: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc12xbw6. DOI: 10.5517/cc12xbw6 HANDLE: 10754/624347 - [Dataset]
Roesle, P., Caporaso, L., Schnitte, M., Goldbach, V., Cavallo, L., & Mecking, S. (2015). CCDC 1010349: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc12xbx7. DOI: 10.5517/cc12xbx7 HANDLE: 10754/624348 - [Dataset]
Roesle, P., Caporaso, L., Schnitte, M., Goldbach, V., Cavallo, L., & Mecking, S. (2015). CCDC 1010350: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc12xby8. DOI: 10.5517/cc12xby8 HANDLE: 10754/624349 - [Dataset]
Roesle, P., Caporaso, L., Schnitte, M., Goldbach, V., Cavallo, L., & Mecking, S. (2015). CCDC 1010351: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc12xbz9. DOI: 10.5517/cc12xbz9 HANDLE: 10754/624350
ae974a485f413a2113503eed53cd6c53
10.1021/ja508447d