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dc.contributor.authorSmit, Wietse
dc.contributor.authorEkeli, Jonas Brattebø
dc.contributor.authorOcchipinti, Giovanni
dc.contributor.authorWozniak, Bartosz
dc.contributor.authorTörnroos, Karl Wilhelm
dc.contributor.authorJensen, Vidar Remi
dc.PublishedOrganometallics. 2020, 39 (3), 397-407.
dc.description.abstractRu-alkylidenes bearing sterically demanding arylthiolate ligands (SAr) constitute one of only two classes of catalyst that are Z-selective in metathesis of 1-alkenes. Of particular interest are complexes bearing pyridine as a stabilizing donor ligand, [RuCl(SAr)(═CHR)(NHC)(py)] (R = phenyl or 2-thienyl, NHC = N-heterocyclic carbene, py = pyridine), which initiate catalysis rapidly and give appreciable yields combined with moderate to high Z-selectivity within minutes at room temperature. Here, we extend this chemistry by synthesizing and testing the first two such complexes (5a and 5b) bearing 3-phenylindenylidene, a ligand known to promote stability in other ruthenium-based olefin metathesis catalysts. The steric pressure resulting from the three bulky ligands (the NHC, the arylthiolate, and the indenylidene) forces the thiolate ligand to position itself trans to the NHC ligand, a configuration different from that of the corresponding alkylidenes. Surprisingly, although this configuration is incompatible with Z-selectivity and slows down pyridine dissociation, the two new complexes initiate readily at room temperature. Although their thermal stability is lower than that of typical indenylidene-bearing catalysts, 5a and 5b are fairly stable in catalysis (TONs up to 2200) and offer up to ca. 80% of the Z-isomer in prototypical metathesis homocoupling reactions. Density functional theory (DFT) calculations confirm the energetic cost of dissociating pyridine from 5a (= M1-Py) to generate 14-electron complex M1. Whereas the latter isomer does not give a metathesis-potent allylbenzene π-complex, it may isomerize to M1-trans and M2, which both form π-complexes in which the olefin is correctly oriented for cycloaddition. The olefin orientation in these complexes is also indicative of Z-selectivity.en_US
dc.publisherAmerican Chemical Societyen_US
dc.rightsNavngivelse 4.0 Internasjonal*
dc.titleZ-Selective Monothiolate Ruthenium Indenylidene Olefin Metathesis Catalystsen_US
dc.typeJournal articleen_US
dc.typePeer revieweden_US
dc.rights.holderCopyright 2020 American Chemical Societyen_US
dc.relation.projectNotur/NorStore: NS2506Ken_US
dc.relation.projectNotur/NorStore: NN2506Ken_US
dc.relation.projectNorges forskningsråd: 239288en_US
dc.relation.projectNorges forskningsråd: 226244en_US
dc.relation.projectNorges forskningsråd: 208335en_US
dc.identifier.citationOrganometallics. 2020, 39 (3), 397–407en_US

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Except where otherwise noted, this item's license is described as Navngivelse 4.0 Internasjonal