Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Concept

Substitution radicalaire

Publications associées (31)

New Applications of 1,3,2-Diazaphospholenes in Catalysis

Johannes Klett

The constant urge to construct new molecules in an economical and sustainable fashion led to the development of numerous metal-catalyzed transformations. Organocatalysts consisting of abundant and more sustainable elements offer an elegant solution to over ...

EPFL2024

Novel Alkynylation Methods through the Combination of Hypervalent Iodine Reagents and Alkynyl-trifluoroborate Salts

Julien Aymeric Borrel

The alkyne motif is a versatile functional group often encountered in organic chemistry. It can be involved in various transformations such as the alkyne-azide cycloaddition and has found widespread application in medicinal chemistry, chemical biology and ...

EPFL2024

Hypervalent Iodine: New Reagents and Functionalization of Peptides

Eliott Hugo Joran Le Du

Alkynes are found in a multitude of natural or synthetic bioactive compounds. In addition to the capacity of these chemical motifs to impact the physicochemical properties of a molecule of interest, the well-established reactivity of alkynes makes them ide ...

EPFL2023

Reactivity of Bromine Radical with Dissolved Organic Matter Moieties and Monochloramine: Effect on Bromate Formation during Ozonation

Urs von Gunten, Sung Eun Lim

Bromine radical (Br center dot) has been hypothesized to be a key intermediate of bromate formation during ozonation. Once formed, Br center dot further reacts with ozone to eventually form bromate. However, this reaction competes with the reaction of Br c ...

AMER CHEMICAL SOC2023

Evaluation of the role of superoxide radical as chain carrier for the formation of hydroxyl radical during ozonation

Urs von Gunten, Gang Yu

Superoxide radicals (O-2(center dot-)) have been suggested as an important chain carrier in the radical chain reaction that promotes ozone (O-3) decomposition to hydroxyl radicals ((OH)-O-center dot) during ozonation. However, due to the difficulty in meas ...

PERGAMON-ELSEVIER SCIENCE LTD2023

Detecting the metabolism of individual yeast mutant strain cells when aged, stressed or treated with antioxidants with diamond magnetometry

Mayeul Sylvain Chipaux

Free radicals play a key role in the ageing process. However, free radicals are small, reactive and short lived and thus challenging to measure. We utilize a new technique called diamond magnetometry for this pur-pose. We make use of nitrogen vacancy cente ...

ELSEVIER SCI LTD2023

Critical Review on Bromate Formation during Ozonation and Control Options for Its Minimization

Urs von Gunten

Ozone is a commonly applied disinfectant and oxidantin drinkingwater and has more recently been implemented for enhanced municipalwastewater treatment for potable reuse and ecosystem protection. Onedrawback is the potential formation of bromate, a possible ...

AMER CHEMICAL SOC2023

Bacterial inactivation in sunlit surface waters is dominated by reactive species that emanate from the synergy between light, iron, and natural organic matter

César Pulgarin, Stefanos Giannakis, Jun Ma

In this study, the synergistic and antagonistic effects of Fe species and coexisting natural organic matter (NOM) on the efficacy of solar light disinfection of water are investigated. Different initial iron species (Fe2+/Fe3+) and naturalorganic matter ty ...

Elsevier2023

Influence of DNP Polarizing Agents on Biochemical Processes: TEMPOL in Transient Ischemic Stroke

Mor-Miri Mishkovsky, Jean-Noël Hyacinthe, Thanh Phong Kevin Lê, Mario Gaetano Lepore, Lara Buscemi Estefanell

Hyperpolarization of 13C by dissolution dynamic nuclear polarization (dDNP) boosts the sensitivity of magnetic resonance spectroscopy (MRS), making possible the monitoring in vivo and in real time of the biochemical reactions of exogenously infused 13C-lab ...

2023

A Simple, Transition Metal Catalyst-Free Method for the Design of Complex Organic Building Blocks Used to Construct Porous Metal-Organic Frameworks

Wendy Lee Queen, Ilia Kochetygov, Till Marian Schertenleib, Jordi Espin Marti, Anita Justin, Jocelyn Richard Roth, Nazanin Taheri

The design of metal-organic frameworks (MOFs) having large pore sizes and volumes often requires the use of complex organic ligands, currently synthesized using costly and time-consuming palladium-catalyzed coupling chemistry. Thus, in the present work, a ...

Wiley-VCH Verlag GmbH2023

Modelling the coupled mercury-halogen-ozone cycle in the central Arctic during spring

Julia Schmale, Ivo Fabio Beck, Hélène Paule Angot

Near-surface mercury and ozone depletion events occur in the lowest part of the atmosphere during Arctic spring. Mercury depletion is the first step in a process that transforms long-lived elemental mercury to more reactive forms within the Arctic that are ...

2023

Oxidase-Type C-H/C-H Coupling Using an Isoquinoline-Derived Organic Photocatalyst

Xile Hu, Lei Zhang

Oxidase-type oxidation is an attractive strategy in organic synthesis due to the use of O-2 as the terminal oxidant. Organic photocatalysis can effect metal-free oxidase chemistry. Nevertheless, current methods are limited in reaction scope, possibly due t ...

Wiley-VCH Verlag GmbH2022

Secondary aerosol formation during the dark oxidation of residential biomass burning emissions

Athanasios Nenes

Particulate matter from biomass burning emissions affects air quality, ecosystems and climate; however, quantifying these effects requires that the connection between primary emissions and secondary aerosol production is firmly established. We performed at ...

ROYAL SOC CHEMISTRY2022

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

Copper-catalyzed transformations of carboradicals generated by electrochemical and photochemical methods: oxidative amination and polyfluoroarylation

Xiangli Yi

Organic radicals are highly active species that can undergo various transformations. Electrochemistry and photochemistry are efficient methods for the generation of these species of high energy, through single electron transfer processes under mild conditi ...

EPFL2021

Nighttime chemistry of biomass burning emissions in urban areas: A dual mobile chamber study

Athanasios Nenes

Residential biomass burning for heating purposes is an important source of air pollutants during winter. Here we test the hypothesis that significant secondary organic aerosol production can take place even during winter nights through oxidation of the emi ...

Copernicus GmbH2021

Photocatalytic Decarboxylative Coupling of Aliphatic N-hydroxyphthalimide Esters with Polyfluoroaryl Nucleophiles

Xile Hu, Runze Mao, Xiangli Yi, Lara Lavrencic

Polyfluoroarenes are an important class of compounds in medical and material chemistry. The synthesis of alkylated polyfluoroarenes remains challenging. Here we describe a decarboxylative coupling reaction of N-hydroxyphthalimide esters of aliphatic carbox ...

Wiley-VCH Verlag GmbH2021

Quantum Sensing of Free Radicals in Primary Human Dendritic Cells

Mayeul Sylvain Chipaux

Free radicals are crucial indicators for stress and appear in all kinds of pathogenic conditions, including cancer, cardiovascular diseases, and infection. However, they are difficult to detect due to their reactivity and low abundance. We use relaxometry ...

AMER CHEMICAL SOC2022

Optical properties and photochemical production of hydroxyl radical and singlet oxygen after ozonation of dissolved organic matter

Urs von Gunten, Frank Jonathan Leresche

This study focuses on the effects of ozonation on the optical and photochemical properties of dissolved organic matter (DOM). Upon ozonation, a decrease in light absorption properties of DOM was observed concomitantly with a large increase in singlet oxyge ...

ROYAL SOC CHEMISTRY2021

Development of remote C-H bond functionalization of redox-active alcohol derivatives and oxidative transformations under photoredox catalysis

Alexandre Julien Florent Leclair

The development of radical-based remote C(sp3)-H functionalizations of redox-active alcohol derivatives, oxidative cycloaddition and rearrangement transformations under visible light photocatalysis constitute the basis of this thesis. The first chapter des ...

EPFL2021