Publications by Oleg Vechorkin

Synthesis and electronic properties of a pentafluoroethyl-derivatized nickel pincer complex

The synthesis of a bis(amino)amide nickel pincer complex bearing a perfluoroethyl ligand was effected by reaction of the corresponding nickel chloride complex with cesium fluoride and trimethyl(pentafluoroethyl)silane. Electrochemical experiments revealed ...

Royal Society of Chemistry2012

A Well-Defined Ni Pincer Catalyst for Cross Coupling of Non-Activated Alkyl Halides and Direct C-H Alkylation

Oleg Vechorkin

Carbon-carbon bond forming reactions are among the most important and useful methods for organic synthesis. During the last years, significant progress has been made in this field. Whereas many catalysts were developed for the coupling of aryl, alkenyl, an ...

EPFL2011

Cross coupling of non-activated alkyl halides with alkynyl Grignard reagents catalyzed by a well-defined Ni pincer complex

Rosario Scopelliti, Aurélien Godinat, Oleg Vechorkin, Xile Hu

The nickel pincer complex 1 catalyzes the cross-coupling of the title compounds with remarkable substrate scope and functional group tolerance. A nickel/alkynyl species was isolated and shown to be catalytically competent. THF=tetrahydrofuran, O-TMEDA=bis[ ...

Wiley-VCH Verlag GmbH2011

Pd, Pt, and Ru complexes of a pincer bis(amino)amide ligand

Rosario Scopelliti, Oleg Vechorkin, Xile Hu, Isuf Salihu, Peng Ren

An improved synthesis of pincer ligand bis[(2-dimethylamino)phenyl]amine (MeN2NH) was reported. Reaction of the Li complex of MeN2N with suitable Pd, Pt, and Ru precursors gave the corresponding metal complexes. The structures of the Pd, Pt, and Ru complex ...

Royal Society of Chemistry2011

A Structure-Activity Study of Ni-Catalyzed Alkyl-Alkyl Kumada Coupling. Improved Catalysts for Coupling of Secondary Alkyl Halides

Rosario Scopelliti, Oleg Vechorkin, Xile Hu, Peng Ren, Kim Dimuth Von Allmen

A structure–activity study was carried out for Ni catalyzed alkyl–alkyl Kumada-type cross coupling reactions. A series of new nickel(II) complexes including those with tridentate pincer bis(amino)amide ligands (RN2N) and those with bidentate mixed amino-am ...

2011

Why are (NN2)Ni pincer complexes active for alkyl-alkyl coupling: ß-H elimination is kinetically accessible but thermodynamically uphill

Rosario Scopelliti, Anne-Clémence Corminboeuf, Oleg Vechorkin, Xile Hu, Jan Breitenfeld

Isomerization and olefin exchange experiments show that β-H elimination is kinetically viable but thermodynamically unfavorable in [(MeNN2)Ni-alkyl] complexes. The intermediacy of Ni-hydride species was corroborated by a trapping experiment. The alkyl comp ...

American Chemical Society2010

The Nickel/Copper-Catalyzed Direct Alkylation of Heterocyclic C-H Bonds

Oleg Vechorkin, Xile Hu, Valérie Proust

A general and straightforward protocol for the cross-coupling of non-activated alkyl halides with heterocyclic CH bonds has been developed. The transformation is chemo- and regioselective and many functional groups on both coupling partners are tolerated. ...

Wiley-VCH Verlag GmbH2010

Carbon Dioxide as the C1 Source for Direct C−H Functionalization of Aromatic Heterocycles

Nathalie Hirt, Oleg Vechorkin, Xile Hu

A simple and straightforward method has been developed for the direct carboxylation of aromatic heterocylces such as oxazoles, thiazoles, and oxadiazoles using CO2 as the C1 source. The reactions require no metal catalyst and only Cs2CO3 as the base. A goo ...

American Chemical Society2010

Ni-Catalyzed Cross Coupling of Non-Activated and Functionalized Alkyl Halides with Alkyl Grignard Reagents

Oleg Vechorkin, Xile Hu

The title reaction is realized by using an isolated NiII complex (1). The catalysis tolerates a wide range of important functional groups that are often incompatible with Grignard reagents in cross-coupling reactions. ...

Wiley-VCH Verlag GmbH2009

Nickel Complexes of a Pincer Amidobis(amine) Ligand: Synthesis, Structure, and Activity in Stoichiometric and Catalytic C—C Bond Forming Reactions of Alkyl Halides

Rosario Scopelliti, Oleg Vechorkin, Xile Hu

NiII complexes of the new pincer amidobis(amine) ligand are described. The Ni chloride complex catalyzes Kumada-Corriu-Tamao coupling of unactivated alkyl halides with alkyl Grignard reagents, as well as double C-C coupling of CH2Cl2 with alkyl Grignard re ...

2009

Ni-Catalyzed Sonogashira Coupling of Non-activated Alkyl Halides: Orthogonal Functionalization of Alkyl Iodides, Bromides, and Chlorides

Delphine Barmaz, Oleg Vechorkin, Xile Hu, Valérie Proust

Ni-catalyzed Sonogashira coupling of nonactivated, β-H- containing alkyl halides, including chlorides, is reported. The coupling is tolerant to a wide range of functional groups, including ether, ester, amide, nitrile, keto, heterocycle, acetal, and aryl h ...

2009

Functional group tolerant Kumada-Corriu-Tamao coupling of non-activated alkyl halides with aryl and heteroaryl nucleophiles: Catalysis by a nickel pincer complex permits the coupling of functionalized Grignard reagents

Oleg Vechorkin, Xile Hu, Valérie Proust

A nickel(II) pincer complex [(MeNN2)NiCl] (1) catalyzes Kumada−Corriu−Tamao cross coupling of nonactivated alkyl halides with aryl and heteroaryl Grignard reagents. The coupling of octyl bromide with phenylmagnesium chloride was used as a test reaction. Us ...

2009

Nickel Complexes of a Pincer NN2 Ligand: Multiple Carbon-Chloride Activation of CH2Cl2 and CHCl3 Leads to Selective Carbon-Carbon Bond Formation

Rosario Scopelliti, Oleg Vechorkin, Xile Hu

A new pincer-type bis(amido)amine (NN2) ligand and its lithium and nickel complexes, including Ni(II) methyl, ethyl, and phenyl complexes, were synthesized. The Ni(II) alkyl complexes react cleanly with alkyl halides including chlorides to form C−C coupled ...

2008