Promotion of selective pathways in isomerizing functionalization of plant oils by rigid framework substituents
AuthorsChristl, Josefine T.
Müller, Gerhard J.
KAUST DepartmentPhysical Sciences and Engineering (PSE) Division
Chemical Science Program
KAUST Catalysis Center (KCC)
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AbstractThe 1,2-(CH2P(1-adamantyl)2)2C6H4 (dadpx) coordinated palladium complex [(dadpx)Pd(OTf)2] (1) is a catalyst precursor for the isomerizing methoxycarbonylation of the internal double bond of methyl oleate, with an unprecedented selectivity (96%) for the linear diester 1,19-dimethyl nonadecanedioate. Rapid formation of the catalytically active solvent-coordinated hydride species [(dadpx)PdH(MeOH)]+ (3-MeOH) is evidenced by NMR spectroscopy, and further isolation and X-ray crystal structure analysis of [(dadpx)PdH(PPh3)]+ (3-PPh3). DFT calculations of key steps of the catalytic cycle unravel methanolysis as the decisive step for enhanced selectivity and the influence of the rigid adamantyl framework on this step by destabilization of transition states of unselective pathways.
SponsorsFinancing by the Stiftung Baden-Wurttemberg (Programm Umwelttechnologieforschung, U14) is acknowledged. P.R. gratefully acknowledges support from the Carl-Zeiss-Foundation by a graduate fellowship. Donation of high oleic sunflower oil methyl ester by Dako AG is acknowledged.
Is Supplemented ByChristl, J. T., Roesle, P., Stempfle, F., Müller, G., Caporaso, L., Cavallo, L., & Mecking, S. (2014). CCDC 992440: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/cc129q69