Koszinowski, Konrad

[["dc.bibliographiccitation.firstpage","13244"],["dc.bibliographiccitation.issue","43"],["dc.bibliographiccitation.journal","Angewandte Chemie International Edition"],["dc.bibliographiccitation.lastpage","13248"],["dc.bibliographiccitation.volume","56"],["dc.contributor.author","Kolter, Marlene"],["dc.contributor.author","Böck, Katharina"],["dc.contributor.author","Karaghiosoff, Konstantin"],["dc.contributor.author","Koszinowski, Konrad"],["dc.date.accessioned","2020-12-10T14:08:24Z"],["dc.date.available","2020-12-10T14:08:24Z"],["dc.date.issued","2017"],["dc.identifier.doi","10.1002/anie.201707362"],["dc.identifier.issn","1433-7851"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/70450"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","Anionic Palladium(0) and Palladium(II) Ate Complexes"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","7752"],["dc.bibliographiccitation.issue","23"],["dc.bibliographiccitation.journal","Chemistry - A European Journal"],["dc.bibliographiccitation.lastpage","7762"],["dc.bibliographiccitation.volume","22"],["dc.contributor.author","Schnegelsberg, Christoph"],["dc.contributor.author","Bachmann, Sebastian"],["dc.contributor.author","Kolter, Marlene"],["dc.contributor.author","Auth, Thomas"],["dc.contributor.author","John, Michael"],["dc.contributor.author","Stalke, Dietmar"],["dc.contributor.author","Koszinowski, Konrad"],["dc.date.accessioned","2018-11-07T10:13:01Z"],["dc.date.available","2018-11-07T10:13:01Z"],["dc.date.issued","2016"],["dc.description.abstract","Grignard reagents RMgCl and their so-called turbo variant, the highly reactive RMgCl center dot LiCl, are of exceptional synthetic utility. Nevertheless, it is still not fully understood which species these compounds form in solution and, in particular, in which way LiCl exerts its reactivity-enhancing effect. A combination of electrospray-ionization mass spectrometry, electrical conductivity measurements, NMR spectroscopy (including diffusion-ordered spectroscopy), and quantum chemical calculations is used to analyze solutions of RMgCl (R=Me, Et, Bu, Hex, Oct, Dec, iPr, tBu, Ph) in tetrahydrofuran and other ethereal solvents in the absence and presence of stoichiometric amounts of LiCl. In tetrahydrofuran, RMgCl forms mononuclear species, which are converted into trinuclear anions as a result of the concentration increase experienced during the electrospray process. These trinuclear anions are theoretically predicted to adopt open cubic geometries, which remarkably resemble structural motifs previously found in the solid state. The molecular constituents of RMgCl and RMgCl center dot LiCl are interrelated via Schlenk equilibria and fast intermolecular exchange processes. A small portion of the Grignard reagent also forms anionic ate complexes in solution. The abundance of these more electron-rich and hence supposedly more nucleophilic ate complexes strongly increases upon the addition of LiCl, thus rationalizing its beneficial effect on the reactivity of Grignard reagents."],["dc.description.sponsorship","Deutsche Forschungsgmeinschaft [KO 2875/4-1]"],["dc.identifier.doi","10.1002/chem.201600699"],["dc.identifier.isi","000380267100015"],["dc.identifier.pmid","27150118"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/40354"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.issn","1521-3765"],["dc.relation.issn","0947-6539"],["dc.title","Association and Dissociation of Grignard Reagents RMgCl and Their Turbo Variant RMgCl center dot LiCl"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","12212"],["dc.bibliographiccitation.issue","53"],["dc.bibliographiccitation.journal","Chemistry – A European Journal"],["dc.bibliographiccitation.lastpage","12218"],["dc.bibliographiccitation.volume","26"],["dc.contributor.author","Kolter, Marlene"],["dc.contributor.author","Koszinowski, Konrad"],["dc.date.accessioned","2021-04-14T08:23:42Z"],["dc.date.available","2021-04-14T08:23:42Z"],["dc.date.issued","2020"],["dc.identifier.doi","10.1002/chem.202001041"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/81018"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-399"],["dc.relation.eissn","1521-3765"],["dc.relation.issn","0947-6539"],["dc.title","Second Comes First: Switching Elementary Steps in Palladium‐Catalyzed Cross‐Coupling Reactions"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","15744"],["dc.bibliographiccitation.issue","44"],["dc.bibliographiccitation.journal","Chemistry - A European Journal"],["dc.bibliographiccitation.lastpage","15750"],["dc.bibliographiccitation.volume","22"],["dc.contributor.author","Kolter, Marlene"],["dc.contributor.author","Koszinowski, Konrad"],["dc.date.accessioned","2018-11-07T10:06:53Z"],["dc.date.available","2018-11-07T10:06:53Z"],["dc.date.issued","2016"],["dc.description.abstract","The reduction of Pd-II precatalysts to catalytically active Pd-0 species is a key step in many palladium-mediated cross-coupling reactions. Besides phosphines, the stoichiometrically used organometallic reagents can afford this reduction, but do so in a poorly understood way. To elucidate the mechanism of this reaction, we have treated solutions of Pd(OAc)(2) and a phosphine ligand L in tetrahydrofuran with RMgCl (R=Ph, Bn, Bu) as well as other organometallic reagents. Analysis of these model systems by electrospray- ionization mass spectrometry found palladate(II) complexes [LnPdR3](-) (n=0 and 1), thus pointing to the occurrence of transmetallation reactions. Upon gas-phase fragmentation, the [LnPdR3](-) anions preferentially underwent a reductive elimination to yield Pd-0 species. The sequence of the transmetallation and reductive elimination, thus, constitutes a feasible mechanism for the reduction of the Pd(OAc)(2) precatalyst. Other species of interest observed include the Pd-IV complex [PdBn5](-), which did not fragment via a reductive elimination but lost BnH instead."],["dc.description.sponsorship","CaSuS (Catalysis for Sustainable Synthesis)"],["dc.identifier.doi","10.1002/chem.201603431"],["dc.identifier.isi","000386795700025"],["dc.identifier.pmid","27717040"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/39182"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.issn","1521-3765"],["dc.relation.issn","0947-6539"],["dc.title","Stability and Unimolecular Reactivity of Palladate(II) Complexes [LnPdR3](-) (L=Phosphine, R=Organyl, n=0 and 1)"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]