Publications associées à Réaction de substitution

The Mononuclear Metal-Binding Site of Mo-Nitrogenase Is Not Required for Activity

The biological N-2-fixation process is catalyzed exclusively by metallocofactor-containing nitrogenases. Structural and spectroscopic studies highlighted the presence of an additional mononuclear metal-binding (MMB) site, which can coordinate Fe in additio ...

Amer Chemical Soc2023

Oxidative rearrangement of 1,1-disubstituted alkenes to ketones

Qian Wang, Jieping Zhu, Qiang Feng

The Wacker process, which is widely used to convert monosubstituted alkenes into the corresponding methyl ketones, is thought to proceed through a PdII/Pd0 catalytic cycle involving a b-hydride elimination step. This mechanistic scenario is inapplicable to ...

American Association for the Advancement of Science2023

CO2 Capture and Release in Amine Solutions: To What Extent Can Molecular Simulations Help Understand the Trends?

Wanda Andreoni, Fabio Pietrucci, Changru Ma

Absorption in amine solutions is a well-established advanced technology for CO2 capture. However, the fundamental aspects of the chemical reactions occurring in solution still appear to be unclear. Our previous investigation of aqueous monoethanolamine (ME ...

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, Jordi Espin Marti, Till Marian Schertenleib, Nazanin Taheri, Ilia Kochetygov, Anita Justin, Jocelyn Richard Roth, Sophia Alessandra Pache

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

Chlorination of amides: Kinetics and mechanisms of formation of N-chloramides and their reactions with phenolic compounds

Urs von Gunten, Tianqi Zhang

Amides are common constituents in natural organic matter and synthetic chemicals. In this study, we investi-gated kinetics and mechanisms of the reactions of chlorine with seven amides, including acetamide, N-meth-ylformamide, N-methylacetamide, benzamide, ...

2023

Bayesian Optimization for Chemical Reactions

Philippe Schwaller, Jeff Guo, Bojana Rankovic

Reaction optimization is challenging and traditionally delegated to domain experts who iteratively pro-pose increasingly optimal experiments. Problematically, the reaction landscape is complex and often requires hundreds of experiments to reach convergence ...

Swiss Chemical Soc2023

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

A mitochondria-specific mutational signature of aging: increased rate of A > G substitutions on the heavy strand

Jacques Fellay, Konstantin Popadin, Dmitrii Iliushchenko, Stepan Denisov

The mutational spectrum of the mitochondrial DNA (mtDNA) does not resemble any of the known mutational signatures of the nuclear genome and variation in mtDNA mutational spectra between different organisms is still incomprehensible. Since mitochondria are ...

OXFORD UNIV PRESS2022

Effect of Co-Substitution on Hydrogen Absorption and Desorption Reactions of YMgNi4-Based Alloys

Andreas Züttel, Loris Giovanni Lombardo, Wen Luo, Heena Yang

YMgNi4-based alloys exhibit reversible hydrogen absorption and desorption reactions at near room temperature. Here, we report that Co-substituted YMgNi4-based alloys exhibited higher hydrogen contents and lower hydrogen absorption and desorption reaction p ...

AMER CHEMICAL SOC2022

Atomistic dynamics of elimination and nucleophilic substitution disentangled for the F- + CH3CH2Cl reaction

Eduardo Carrascosa Casado

Chemical reaction dynamics are studied to monitor and understand the concerted motion of several atoms while they rearrange from reactants to products. When the number of atoms involved increases, the number of pathways, transition states and product chann ...

NATURE PORTFOLIO2021

Alkynyl triazenes enable divergent syntheses of 2-pyrones

Kay Severin, Nicolai Cramer, Carl Thomas Bormann, Jin Fay Tan

The 2-pyrone motif occurs frequently in bioactive natural products and is appreciated as synthetic intermediates. However, only few methods allow for diversifying functional group modifications on this relevant heterocycle. The distinct properties of 1-alk ...

2021

Diamine Synthesis via the Nitrogen-Directed Azidation of sigma- and pi-C-C Bonds

Jérôme Waser, Mingming Wang

Diamines are essential building blocks for the synthesis of agrochemicals, drugs, and organic materials, yet their synthesis remains challenging, as both nitrogens need to be differentiated and diverse substitution patterns (1,2, 1,3, or 1,4) are required. ...

2021

Identifying the origin of local flexibility in a carbohydrate polymer

Klaus Kern, Stephan Rauschenbach, Sabine Abb

Correlating the structures and properties of a polymer to its monomer sequence is key to understanding how its higher hierarchy structures are formed and how its macroscopic material properties emerge. Carbohydrate polymers, such as cellulose and chitin, a ...

National Academy of Sciences2021

Constraining the response factors of an extractive electrospray ionization mass spectrometer for near-molecular aerosol speciation

Julia Schmale, Imad El Haddad, Yandong Tong

Online characterization of aerosol composition at the near-molecular level is key to understanding chemical reaction mechanisms, kinetics, and sources under various atmospheric conditions. The recently developed extractive electrospray ionization time-of-f ...

2021

Facile One-Pot Assembly of Push-Pull Imines by a Selective C-F Substitution Process in Aryl Fluorides

Shubhajit Das

Herein, we report the synthesis of a series of push-pull imines by considering cyclic diamino substituent at the C-centre and fluoroaryl substituent at the N-centre. This has been achieved by a selective aromatic nucleophilic substitution of different fluo ...

WILEY-V C H VERLAG GMBH2020

Understanding How Ligand Functionalization Influences CO2 and N-2 Adsorption in a Sodalite Metal-Organic Framework

Michele Ceriotti, Wendy Lee Queen, Pascal Alexander Schouwink, Mehrdad Asgari, Olga Trukhina, Ilia Kochetygov, Rocio Semino Barbaresi

In this work, a detailed study is conducted to understand how ligand substitution influences the CO, and N-2 adsorption properties of two highly crystalline sodalite metal-organic frameworks (MOFs) known as Cu-BTT (BTT-3 = 1,3,5-benzenetristetrazolate) and ...

AMER CHEMICAL SOC2020

Computational Modeling of the Oxygen Evolution Reaction at Semiconductor-Water Interfaces: A Path Towards Breaking Linear Scaling Relationships

Patrick Gono

Photoelectrochemical water splitting is a promising source of clean, renewable fuel in the form of hydrogen. Despite extensive research endeavors, the widespread adoption of this technology is impeded due to suboptimal catalysts for the oxygen evolution re ...

EPFL2020

Reactions of nitrogen-containing compounds with ozone: kinetics and mechanisms

Sung Eun Lim

Nitrogen-containing moieties are widespread in natural waters in dissolved organic nitrogen and micropollu-tants. They are often susceptible to an electrophilic attack of ozone because of the electron-rich nature of the neutral form of nitrogen in organic ...

EPFL2020

Palladium Catalysed Intramolecular Carbo-oxygenation of Propargylic Amines to Access 1,2-Amino Alcohols and alpha-Amino Ketones via in situ Tether Formation

Phillip Gulliver Dominic Greenwood

a-Amino ketones and 1,2-amino alcohols are important structural motifs in organic chemistry, that can be observed in natural products, pharmaceutically and bioactive compounds. For these reasons, they constitute privileged targets for the development of ne ...

EPFL2020

Synthetic Studies toward Amanita Phalloides Toxins

Philipp Georg Werner Seeberger

Amatoxins are ribosomally synthesized and post-translationally modified bicyclic octapeptides biosynthesized by the deadly basidiomycete fungus Amanita phalloides. Amongst this group, alpha-amanitin is the most widely known toxin and is currently under inv ...

EPFL2020