Konrad Koszinowski
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View article: Intramolecular Phenyl Transfer from Boron to Lithium, Sodium, and Copper: Defining the Limits of Transmetalation
Intramolecular Phenyl Transfer from Boron to Lithium, Sodium, and Copper: Defining the Limits of Transmetalation Open
Transmetalation is a key elementary step in organometallic chemistry, for which reason there is a keen interest in better understanding the factors governing this reaction. We have previously reported the unusual transfer of a phenyl anion…
View article: Competition between One‐ and Two‐Electron Unimolecular Reactions of Late 3d‐Metal Complexes [(Me<sub>3</sub>SiCH<sub>2</sub>)<i><sub>n</sub></i>M]<sup>–</sup>(M = Fe, Co, Ni, and Cu; <i>n</i> = 2–4)
Competition between One‐ and Two‐Electron Unimolecular Reactions of Late 3d‐Metal Complexes [(Me<sub>3</sub>SiCH<sub>2</sub>)<i><sub>n</sub></i>M]<sup>–</sup>(M = Fe, Co, Ni, and Cu; <i>n</i> = 2–4) Open
Although organometallic complexes of the late 3d elements are known to undergo both one‐and two‐electron reactions, their relative propensities to do so remain poorly understood. To gain direct insight into the competition between these di…
View article: Dissecting Transmetalation Reactions at the Molecular Level: Aryl Transfer in Copper-Tetraarylborate Complexes
Dissecting Transmetalation Reactions at the Molecular Level: Aryl Transfer in Copper-Tetraarylborate Complexes Open
Contains fulltext : 316244.pdf (Publisher’s version ) (Open Access)
View article: Reductive Elimination From Tetra‐Alkyl Cuprates [Me<sub><i>n</i></sub>Cu(CF<sub>3</sub>)<sub>4−<i>n</i></sub>]<sup>−</sup> (<i>n</i>=0–4): Beyond Simple Oxidation States
Reductive Elimination From Tetra‐Alkyl Cuprates [Me<sub><i>n</i></sub>Cu(CF<sub>3</sub>)<sub>4−<i>n</i></sub>]<sup>−</sup> (<i>n</i>=0–4): Beyond Simple Oxidation States Open
In recent years, the electronic structures of organocuprates in general and the complex [Cu(CF 3 ) 4 ] − in particular have attracted significant interest. A possible key indicator in this context is the reactivity of these species. Noneth…
View article: Dissecting Transmetalation Reactions at the Molecular Level: Aryl Transfer in Copper-Tetraarylborate Complexes
Dissecting Transmetalation Reactions at the Molecular Level: Aryl Transfer in Copper-Tetraarylborate Complexes Open
Boron-copper transmetalation reactions are practically important, but their detailed mechanisms remain elusive. To im-prove our understanding of these transformations, we have analyzed the systems Cu+/(BArX4)− (ArX = p-X−C6H4 with X = OMe,…
View article: The Fe-MAN Challenge: Ferrates–Microkinetic Assessment of Numerical Quantum Chemistry
The Fe-MAN Challenge: Ferrates–Microkinetic Assessment of Numerical Quantum Chemistry Open
Organometallic species, such as organoferrate ions, are prototypical nucleophiles prone to reacting with a wide range of electrophiles, including proton donors. In solution, the operation of dynamic equilibria and the simultaneous presence…
View article: Elementary Steps of Silver- and Gold-Mediated Trifluoromethylation Reactions
Elementary Steps of Silver- and Gold-Mediated Trifluoromethylation Reactions Open
Due to the importance of the trifluoromethyl group in medicinal chemistry, trifluoromethylation reactions are in high demand. Most of the reported trifluoromethylation protocols rely on copper complexes, whose mechanistic role in these tra…
View article: Intramolecular Phenyl Transfer from a Boronate to Lithium in the Gas Phase Reveals Crucial Role of Solvation in Transmetalations
Intramolecular Phenyl Transfer from a Boronate to Lithium in the Gas Phase Reveals Crucial Role of Solvation in Transmetalations Open
In contrast to its behavior in solution, the adduct [(LiBr)( t Bu)(Ph)Bpin] − (pin=pinacol) transfers its phenyl anion from boron to lithium upon fragmentation in the gas phase. Quantum chemical calculations predict this exceptional transm…
View article: Observation and Characterization of Single Elementary Reactions of Organometallics
Observation and Characterization of Single Elementary Reactions of Organometallics Open
The diversity of organometallic reactivity can be traced back to relatively few elementary steps. Hence, a detailed knowledge of these elementary steps is essential for understanding the mechanism of organometallic reactions. Due to the co…
View article: Gas‐Phase Alkali‐Metal Cation Affinities of Stabilized Enolates
Gas‐Phase Alkali‐Metal Cation Affinities of Stabilized Enolates Open
The chemistry of alkali‐metal enolates is dominated by ion pairing. To improve our understanding of the intrinsic interactions between the alkali‐metal cations and the enolate anions, we have applied Cooks’ kinetic method to determine rela…
View article: Unimolecular Reactivity of [Cu(R)(CF<sub>3</sub>)<sub>3</sub>]<sup>−</sup> Complexes (R=Organyl): Stepwise versus Concerted Mechanism in Copper‐Mediated Trifluoromethylation
Unimolecular Reactivity of [Cu(R)(CF<sub>3</sub>)<sub>3</sub>]<sup>−</sup> Complexes (R=Organyl): Stepwise versus Concerted Mechanism in Copper‐Mediated Trifluoromethylation Open
The cuprate complexes [Cu(R)(CF 3 ) 3 ] − (R=organyl) offer an efficient synthetic access to valuable trifluoromethylation products RCF 3 . Here, electrospray‐ionization mass spectrometry is used to analyze the formation of these intermedi…
View article: Cover Feature: Live Monitoring of Anionic Living Polymerizations by Electrospray‐Ionization Mass Spectrometry (Chem. Eur. J. 13/2023)
Cover Feature: Live Monitoring of Anionic Living Polymerizations by Electrospray‐Ionization Mass Spectrometry (Chem. Eur. J. 13/2023) Open
Electrospray-ionization mass spectrometry easily distinguishes the different living oligomers resulting from the anionic ring-opening polymerization of the acceptor-substituted cyclopropane Mcyclic. Kinetic modeling reproduces the measured…
View article: C versus O Protonation in Zincate Anions: A Simple Gas‐Phase Model for the Surprising Kinetic Stability of Organometallics
C versus O Protonation in Zincate Anions: A Simple Gas‐Phase Model for the Surprising Kinetic Stability of Organometallics Open
For better understanding the intrinsic reactivity of organozinc reagents, we have examined the protolysis of the isolated zincate ions Et 3 Zn − , Et 2 Zn(OH) − , and Et 2 Zn(OH) 2 Li − by 2,2,2‐trifluoroethanol in the gas phase. The proto…
View article: Live Monitoring of Anionic Living Polymerizations by Electrospray‐Ionization Mass Spectrometry
Live Monitoring of Anionic Living Polymerizations by Electrospray‐Ionization Mass Spectrometry Open
Anionic polymerizations are of exceptional practical importance, but difficult to analyze due to the high reactivity of the growing polymer chains. Here, we demonstrate that electrospray‐ionization mass spectrometry (ESI‐MS) permits direct…
View article: In‐Situ Analysis of Anionic Coordination Polymerizations by Electrospray‐Ionization Mass Spectrometry
In‐Situ Analysis of Anionic Coordination Polymerizations by Electrospray‐Ionization Mass Spectrometry Open
Anionic coordination polymerizations proceed via highly reactive intermediates, whose in situ analysis has remained difficult. Here, we show that electrospray‐ionization mass spectrometry is a promising method to obtain detailed informatio…
View article: Microscopic Reactivity of Phenylferrate Ions toward Organyl Halides
Microscopic Reactivity of Phenylferrate Ions toward Organyl Halides Open
Despite its practical importance, organoiron chemistry remains poorly understood due to its mechanistic complexity. Here, we focus on the oxidative addition of organyl halides to phenylferrate anions in the gas phase. By mass‐selecting ind…
View article: Origin of the different reactivity of the high‐valent coinage‐metal complexes [RCu <sup> <scp>iii</scp> </sup> Me <sub>3</sub> ] <sup>−</sup> and [RAg <sup> <scp>iii</scp> </sup> Me <sub>3</sub> ] <sup>−</sup> (R=allyl)**
Origin of the different reactivity of the high‐valent coinage‐metal complexes [RCu <sup> <span>iii</span> </sup> Me <sub>3</sub> ] <sup>−</sup> and [RAg <sup> <span>iii</span> </sup> Me <sub>3</sub> ] <sup>−</sup> (R=allyl)** Open
High‐valent tetraalkylcuprates( iii ) and ‐argentates( iii ) are key intermediates of copper‐ and silver‐mediated C−C coupling reactions. Here, we investigate the previously reported contrasting reactivity of [RM iii Me 3 ] − complexes (M=…
View article: Origin of the different reactivity of the high-valent coinage-metal complexes [RCuIIIMe3]− and [RAgIIIMe3]− (R = allyl)
Origin of the different reactivity of the high-valent coinage-metal complexes [RCuIIIMe3]− and [RAgIIIMe3]− (R = allyl) Open
High-valent tetraalkylcuprates(III) and -argentates(III) are key intermediates of copper and silver-mediated C−C coupling reactions. Here, we investigate the previously reported contrasting reactivity of [RM III Me 3 ] − complexes (M = Cu,…
View article: Origin of the different reactivity of the high-valent coinage-metal complexes [RCuIIIMe3]− and [RAgIIIMe3]− (R = allyl)
Origin of the different reactivity of the high-valent coinage-metal complexes [RCuIIIMe3]− and [RAgIIIMe3]− (R = allyl) Open
High-valent tetraalkylcuprates(III) and -argentates(III) are key intermediates of copper and silver-mediated C−C coupling reactions. Here, we investigate the previously reported contrasting reactivity of [RM III Me 3 ] − complexes (M = Cu,…
View article: Phenyl argentate aggregates [AgnPhn<b>+</b>1]<b>−</b> (n <b>=</b> 2–8): Models for the self-assembly of atom-precise polynuclear organometallics
Phenyl argentate aggregates [AgnPhn<b>+</b>1]<b>−</b> (n <b>=</b> 2–8): Models for the self-assembly of atom-precise polynuclear organometallics Open
Electrospray ionization of phenyl argentates formed by transmetalation reactions between phenyl lithium and silver cyanide provides access to the argentate aggregates, [AgnPhn+1]−, which were individually mass-selected for n = 2–8 in order…
View article: CCDC 1909827: Experimental Crystal Structure Determination
CCDC 1909827: Experimental Crystal Structure Determination Open
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available …
View article: CCDC 1909829: Experimental Crystal Structure Determination
CCDC 1909829: Experimental Crystal Structure Determination Open
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available …
View article: CCDC 1909828: Experimental Crystal Structure Determination
CCDC 1909828: Experimental Crystal Structure Determination Open
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available …
View article: CCDC 1909831: Experimental Crystal Structure Determination
CCDC 1909831: Experimental Crystal Structure Determination Open
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available …
View article: CCDC 1909830: Experimental Crystal Structure Determination
CCDC 1909830: Experimental Crystal Structure Determination Open
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available …
View article: Supramolecular Self‐Assembly of β<sup>3</sup>‐Peptides Mediated by Janus‐Type Recognition Units
Supramolecular Self‐Assembly of β<sup>3</sup>‐Peptides Mediated by Janus‐Type Recognition Units Open
To gain mechanistic insights, natural systems with biochemical relevance are inspiring for the creation of new biomimetics with unique properties and functions. Despite progress in rational design and protein engineering, folding and intra…
View article: Second Comes First: Switching Elementary Steps in Palladium‐Catalyzed Cross‐Coupling Reactions
Second Comes First: Switching Elementary Steps in Palladium‐Catalyzed Cross‐Coupling Reactions Open
The electron‐poor palladium(0) complex L 3 Pd (L=tris[3,5‐bis(trifluoromethyl)phenyl]phosphine) reacts with Grignard reagents RMgX and organolithium compounds RLi via transmetalation to furnish the anionic organopalladates [L 2 PdR] − , as…
View article: Modulation of Gas-Phase Lithium Cation Basicities by Microsolvation
Modulation of Gas-Phase Lithium Cation Basicities by Microsolvation Open
In contrast to the extensive knowledge of lithium cation affinities and basicities, the thermochemistry of microsolvated lithium cations is much less explored. Here, we determine the relative stabilities of Li(A,B)n+ complexes, n = 2 and 3…