Publications de Alexander Tskhovrebov

Novel cationic 1,2,4-selenadiazoles: synthesis via addition of 2-pyridylselenyl halides to unactivated nitriles, structures and four-center SeMIDLINE HORIZONTAL ELLIPSISN contacts

2-Pyridylselenyl halides undergo facile coupling with a triple CN bond of unactivated nitriles. Unprecedented heterocyclization allowed the preparation of a novel class of cationic 1,2,4-selenadiazoles in remarkably high yields. Cationic 1,2,4-selenadiazol ...

ROYAL SOC CHEMISTRY2021

Synthesis of aminyl biradicals by base-induced Csp3–Csp3 coupling of cationic azo dyes

Andrzej Sienkiewicz, Kay Severin, Rosario Scopelliti, Euro Solari, Léonard Yannick Maurice Eymann, Alexander Tskhovrebov, Alberto Fabrizio, Farzaneh Fadaei Tirani, Yizhu Liu, Ophélie Marie Planes, Paul Varava

2019

Palladium(II)-Stabilized Pyridine-2-Diazotates: Synthesis, Structural Characterization, and Cytotoxicity Studies

Paul Joseph Dyson, Alexander Tskhovrebov, Tina Riedel

Well-defined diazotates are scarce. Here we report the synthesis of unprecedented homoleptic palladium(II) diazotate complexes. The palladium(II)-mediated nitrosylation of 2-aminopyridines with NaNO2 results in the formation of metal-stabilized diazotates, ...

2018

Neutral Aminyl Radicals Derived from Azoimidazolium Dyes

Andrzej Sienkiewicz, Kay Severin, Rosario Scopelliti, Euro Solari, Philip Pattison, Laurent Alexis Clément Vannay, Henrik Moodysson Rønnow, Léonard Yannick Maurice Eymann, Ivica Zivkovic, Matthew Wodrich, Alexander Tskhovrebov, José Luis Bila

The synthesis and characterization of a new class of neutral aminyl radicals is reported. Monoradicals were obtained by reduction of azoimidazolium dyes with potassium. Structural, spectroscopic, and computational data suggest that the spin density is cent ...

2016

Preparation of cationic azo compounds

Kay Severin, Alexander Tskhovrebov

The present invention relates to a novel method for preparing cationic azo compounds, which preferably can be used as dyes. Further, the invention relates to novel cationic azo compounds and the use of N2O in the synthesis of azo-imidazolium dyes. ...

2016

Synthesis of Azoimidazolium Dyes with Nitrous Oxide

Kay Severin, Rosario Scopelliti, Euro Solari, Alexander Tskhovrebov

A new method for the synthesis of industrially important azoimidazolium dyes is presented. The procedure is based on a reagent which is rarely used in the context of synthetic organic chemistry: nitrous oxide (“laughing gas”). N2O is first coupled to N-het ...

Wiley-Blackwell2015

Activation of Nitrous Oxide

Alexander Tskhovrebov

EPFL2014

Reactions of Grignard Reagents with Nitrous Oxide

Kay Severin, Rosario Scopelliti, Euro Solari, Alexander Tskhovrebov

The chemical activation of nitrous oxide (N2O) can be achieved by organocalcium, organosodium, and organolithium compounds. Grignard reagents, on the other hand, are believed to be inert. We demonstrate that this generalization is not correct. Some aliphat ...

American Chemical Society2014

Insertion of Zerovalent Nickel into the N–N Bond of N-Heterocyclic-Carbene-Activated N2O

Kay Severin, Rosario Scopelliti, Euro Solari, Alexander Tskhovrebov

Metal-mediated cleavage of the N–N bond is a rarely observed phenomenon in the chemistry of nitrous oxide (N2O). We demonstrate that, upon activation of N2O with N-heterocyclic carbenes, zerovalent nickel is able to insert into the N–N bond to give nitrosy ...

Amer Chemical Soc2013

Adducts of Nitrous Oxide and N-Heterocyclic Carbenes: Syntheses, Structures, and Reactivity

Kay Severin, Rosario Scopelliti, Euro Solari, Basile Vuichoud, Alexander Tskhovrebov

N-Heterocyclic carbenes (NHCs) react at ambient conditions with nitrous oxide to give covalent adducts. In the crystal, all compounds show a bent N2O group connected via the N-atom to the former carbene carbon atom. Most adducts are stable at room temperat ...

Amer Chemical Soc2013

Activation of Nitrous Oxide by Dinuclear Ruthenium Complexes

Kay Severin, Rosario Scopelliti, Euro Solari, Alexander Tskhovrebov

The dinuclear Ru(II) complexes (arene)Ru(μ-Cl)3RuCl(C2H4)(PCy3) (arene = p-cymene or 1,3,5-C6H3iPr3) react with N2O under mild conditions to give OPCy3 and the trinuclear complexes (arene)Ru(μ-Cl)3Ru(μ-Cl)3Ru(arene). The N-heterocyclic carbene complex (p-c ...

American Chemical Society2012

Sequential N–O and N–N Bond Cleavage of N-Heterocyclic Carbene-Activated Nitrous Oxide with a Vanadium Complex

Kay Severin, Rosario Scopelliti, Euro Solari, Matthew Wodrich, Alexander Tskhovrebov

Chemically induced bond cleavage of nitrous oxide typically proceeds by rupture of the N–O bond with concomitant O-atom transfer and liberation of dinitrogen. On a few occasions, N–N bond scission has been observed instead. We report a reaction sequence in ...

2012

Covalent Capture of Nitrous Oxide by N-Heterocyclic Carbenes

Kay Severin, Rosario Scopelliti, Euro Solari, Matthew Wodrich, Alexander Tskhovrebov

A good catch: N-heterocyclic carbenes (NHCs) form stable adducts with nitrous oxide (N2O) under mild reaction conditions. The adducts display unique reactivity as evidenced by an alkylation reaction which leads to a rupture of the NN bond. ...

Wiley-Blackwell2012