Publications associées à Synthetic studies towards Lundurines A-C

Photocatalyzed [2σ + 2σ] and [2σ + 2π] Cycloadditions for the Synthesis of Bicyclo[3.1.1]heptanes and 5- or 6-Membered Carbocycles

Matthew Wodrich, Jérôme Waser, André Bossonnet

We report the use of photocatalysis for the homolytic ring-opening of carbonyl cyclopropanes. In contrast to previous studies, our approach does not require a metal cocatalyst or a strong reductant. The carbonyl cyclopropanes can be employed for both [2σ + ...

2023

The acid-mediated isomerization of iridium(iii) complexes with cyclometalated NHC ligands: kinetic vs. thermodynamic control

Kay Severin, Farzaneh Fadaei Tirani, Anastasia Gitlina

The isomerization of iridium(III) complexes with metalated N-heterocyclic carbene (NHC) ligands was studied. The fac isomers of complexes with 1-phenyl-3-methylbenzimidazolin-2-ylidene or 1-phenyl-3-benzylbenzimidazolin-2-ylidene ligands are transformed cl ...

2023

Synthesis, isolation and application of a sila-ketenyl anion

Rosario Scopelliti, Shiori Fujimori

Ynolates or ketenyl anions, [RCCO]-, are negatively charged reactive intermediates, which can be generated in situ and used for divergent chemical transformations. Ynolates can react either at the oxygen or carbon centres or across the C-C triple bond, mak ...

Springernature2023

N-Terminal Selective C-H Azidation of Proline-Containing Peptides: a Platform for Late-Stage Diversification

Jérôme Waser, Raphaël Michel Henri Simonet-Davin, Emmanuelle Madeline Dominique Allouche

A methodology for the C-H azidation of N-terminal proline-containing peptides was developed employing only commercially available reagents. Peptides bearing a broad range of functionalities and containing up to 6 amino acids were selectively azidated at th ...

2022

Photochemical Alkynylations with Hypervalent Iodine Reagents

Stephanie Grace Elizabeth Amos

Over the past twenty years, photochemical transformations have gained in importance in organic chemistry. Indeed, the development of photocatalysts has allowed the use of visible light as an energy source for chemical transformations. More specifically, ph ...

EPFL2022

Isolation, Characterisation and Reactivity of N-Heterocyclic Diazoolefins

Paul Varava

Examples for applications of nitrous oxide in organic synthesis remain rare up until today. First mayor contributions of our group were published in 2012, when nitrous oxide was successfully captured by N-heterocyclic carbenes. Subsequent studies investiga ...

EPFL2022

Synthetic chemistry with nitrous oxide and triazenes

Iris Roswitha Landman

Nitrous oxide (N2O) has gained much interest because of its physiological effects ("laughing gas") and its negative environmental impact ("greenhouse gas", "ozone-depleting substance"): It has a lifetime of more than 100 years in the atmosphere. Its persis ...

EPFL2022

Multiple Surface Site Three-Dimensional Structure Determination of a Supported Molecular Catalyst

David Benjamin Roger Antoine Gajan, Pierrick Berruyer, Moreno Lelli, Zhuoran Wang

The structural characterization of supported molecular catalysts is challenging due to the low density of active sites and the presence of several organic/organometallic surface groups resulting from the often complex surface chemistry associated with supp ...

AMER CHEMICAL SOC2022

Ring-Opening Reactions of Aminocyclopropanes and Aminocyclobutanes

Mingming Wang

Nitrogen-containing compounds are an important class of molecules in medicinal chemistry, chemical biology, biochemistry, material sciences or environmental sciences. Organic nitrogen occurs in many forms, ranging from small building blocks such as urea, a ...

EPFL2022

Atomic Level Insights of Non-Noble Metal Catalysts for the Oxygen Evolution Reaction

Lichen Bai

The conversion of intermittent renewable energy resources in the form of chemical bond, such as hydrogen production from electrochemical water splitting, is a promising way to satisfy the future global energy demand and address the environmental issues. Th ...

EPFL2021

Three-membered cyclic digermylenes stabilised by an N-heterocyclic carbene dagger

Zhaowen Dong

Treatment of potassium salts of silole dianions with donor stabilised germanium dichlorides gave the anticipated silagermafulvenylidenes R2Si = Ge(Do) (R2Si = 1-silacyclopentadiendiyl, Do = N-heterocyclic carbene (NHC)) only as transient intermediates in a ...

2021

New Vinylation and Alkynylation Strategies with Hypervalent Iodine Reagents and Diazo Compounds

Guillaume Dominique Pisella

The development of a sequential copper-catalyzed oxy-alkynylation/intramolecular [4+2] cycloaddition of allenes and arenes was investigated at first. This one-pot protocol allowed the construction of complex polycylic architectures with high efficiency fro ...

EPFL2021

Tuning the π‐Accepting Properties of Mesoionic Carbenes: A Combined Computational and Experimental Study

Andrzej Sienkiewicz, Kay Severin, Rosario Scopelliti, Anne-Clémence Corminboeuf, Farzaneh Fadaei Tirani, Jacob Terence Blaskovits, Zhaowen Dong

Mesoionic imidazolylidenes are recognized as excellent electron-donating ligands in organometallic and main group chemistry. However, these carbene ligands typically show poor π-accepting properties. We have performed a computational analysis of 71 mesoion ...

2021

Using collective knowledge to assign oxidation states of metal cations in metal-organic frameworks

Seyedmohamad Moosavi, Berend Smit, Daniele Ongari, Kevin Maik Jablonka

Knowledge of the oxidation state of metal centres in compounds and materials helps in the understanding of their chemical bonding and properties. Chemists have developed theories to predict oxidation states based on electron-counting rules, but these can f ...

NATURE RESEARCH2021

Carbon Dioxide Reduction by Multimetallic Uranium(IV) Complexes Supported by Redox-Active Schiff Base Ligands

Rosario Scopelliti, Marinella Mazzanti, Marta Falcone, Nadir Jori

The synthesis, structure, and reactivity with CO2 and CS2 of new U(IV) complexes with a redox-active Schiff base are reported. The reaction of UI3 with the heptadentate Schiff base ligand 2,2',2 ''-tris(salicylideneimino)-triethylamine (trensal) did not le ...

2020

Modular Chiral N-Heterocyclic Carbene Ligands for the Nickel-Catalyzed Enantioselective C-H Functionalization of Heterocycles

Nicolai Cramer, Johannes Diesel

N-Heterocyclic carbenes (NHCs) are the ligands of choice in a large variety of transformations entailing different transition metals. However, the number and variety of chiral NHCs suitable as stereo-controlling ligands in asymmetric catalysis remains limi ...

2020

Oxygen evolution reaction catalyzed by first-row transition metal oxides: stability and mechanism

Aliki Moysiadou

Water splitting offers the opportunity for storing solar energy and, thus, producing carbon-neutral and renewable solar fuels. The process, known as artificial photosynthesis, is limited by the electrocatalytic conversion of water into molecular oxygen. El ...

EPFL2020

Light-Activated, Bioadhesive, Poly(2-hydroxyethyl methacrylate) Brush Coatings

Dominique Pioletti, Harm-Anton Klok, Nariye Cavusoglu Ataman, Peyman Karami, Jian Wang

Rapid adhesion between tissue and synthetic materials is relevant to accelerate wound healing and to facilitate the integration of implantable medical devices. Most frequently, tissue adhesives are applied as a gel or a liquid formulation. This manuscript ...

American Chemical Society2020

Vinyl and Alkynyl Triazenes: Synthesis, Reactivity, and Applications

Kay Severin, Abdusalom Suleymanov

Aromatic compounds containing triazenyl groups (N3RR′) have a profound impact on synthetic organic and medicinal chemistry. In contrast, the chemistry of vinyl and alkynyl triazenes was a largely uncharted territory until recently. The situation has change ...

Wiley-VCH Verlag GmbH2021

Multihole water oxidation catalysis on haematite photoanodes revealed by operando spectroelectrochemistry and DFT

Michael Graetzel, Matthew Thomas Mayer, Yimeng Ma

Water oxidation is the key kinetic bottleneck of photoelectrochemical devices for fuel synthesis. Despite advances in the identification of intermediates, elucidating the catalytic mechanism of this multi-redox reaction on metal-oxide photoanodes remains a ...

NATURE PUBLISHING GROUP2020