Publications associées à Substitution nucléophile

Development of Sustainable Carbohydrate-Based Solvents by Acetal Functionalisation of Biomass

Organic solvents are ubiquitous in industrial and domestic applications from the production of pharmaceuticals to household consumer products. The negative impact of most traditional solvents, especially aprotic types, on the environment, health, and safet ...

EPFL2024

Divergent Asymmetric Total Synthesis of (−)‐Voacafricines A and B

Qian Wang, Jieping Zhu, Rémi Julien Sylvain Andres

A divergent asymmetric total synthesis of voacafricines A and B, hexacyclic monoterpene indole alkaloids, has been accomplished featuring the following key steps: a)a catalyst-controlled asymmetric Pictet– Spengler reaction of 6-methoxytryptamine with a ch ...

Wiley-VCH Verlag GmbH2023

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

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

Copper-Catalyzed Alkynylation of Hydrazides: An Easy Access to Functionalized Azadipeptides

Jérôme Waser, Eliott Hugo Joran Le Du, Julien Aymeric Borrel

We report a copper-catalyzed alkynylation of azadipeptides using ethynylbenziodoxolone (EBX) reagents. Nonsymmetrical ynehydrazides could be obtained in 25–97% yield using azaglycine derivatives as nucleophiles. The transformation is compatible with most f ...

2022

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

Rh-catalyzed C-H Bond Heteroarylation with Hypervalent Iodine Reagents and Pd-Catalyzed Tethered Functionalizations of Carbon-Carbon Multiple Bonds

Ashis Kumar Das

Transition metal-catalyzed C-H activation is a powerful tool for the synthesis of organic building blocks, materials, and natural products. Over the last decade, directing-group-assisted metal-catalyzed C-H functionalization has attracted increasing intere ...

EPFL2022

Enantio- and diastereoselective construction of vicinal C(sp(3)) centres via nickel-catalysed hydroalkylation of alkenes

Xile Hu, Chao Fan, Srikrishna Bera

In drug discovery, the proportion of aliphatic carbons (C(sp(3))) and the presence of chiral carbons in organic molecules are positively correlated to their chance of clinical success. Although methods exist for the synthesis of chiral C(sp(3))-rich molecu ...

2022

Umpolung Of Electron-Rich Heteroarenes With Hypervalent Iodine Reagents

Jérôme Waser, Raj Kumar Nandi

Five-membered heterocycles are well known for their innate nucleophilicity. In contrast, reaction of these heterocycles as electrophiles is less established and has become only recently an intensively investigated research area in synthetic chemistry. The ...

PERGAMON-ELSEVIER SCIENCE LTD2021

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

Tosyloxybenziodoxolone: A Platform for Performing the Umpolung of Alkynes in One-Pot Transformations

Jérôme Waser, Julien Aymeric Borrel

Ethynylbenziodoxolones (EBXs) are commonly encountered reagents for the electrophilic alkynylation of nucleophiles. Herein, we report a one-pot, two-step process for EBX generation and their direct application in substrate functionalization. Our approach e ...

2021

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

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

Visible-Light-Driven Catalytic Deracemization of Secondary Alcohols

Xile Hu, Zhikun Zhang

Deracemization of racemic chiral compounds is an attractive approach in asymmetric synthesis, but its development has been hindered by energetic and kinetic challenges. Here we describe a catalytic deracemization method for secondary benzylic alcohols whic ...

Wiley-VCH Verlag GmbH2021

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

Oxidative Fluorination of Cyclopropylamides through Organic Photoredox Catalysis

Jérôme Waser, Mingming Wang

We report an oxidative ring-opening strategy to transform cyclopropylamides and cyclobutylamides into fluorinated imines. The imines can be isolated in their more stable hemiaminal form, with the fluorine atom installed selectively at the gamma or delta po ...

Wiley-VCH Verlag GmbH2020

Access to Vinyl Ethers and Ketones with Hypervalent Iodine Reagents as Oxy-Allyl Cation Synthetic Equivalents

Jérôme Waser, Nina Declas

We report an Umpolung strategy of enol ethers to generate oxy-allyl cation equivalents based on the use of hypervalent iodine reagents. Under mild basic conditions, the addition of nucleophiles to aryloxy-substituted vinylbenziodoxolone (VBX) reagents, eas ...

Wiley-VCH Verlag GmbH2020

Organocatalysts in C-N Bond Forming Reactions of Amines with CO2

Martin Hulla

The thesis describes a simple approach for N-formylation of amines with CO2 and hydrosilane reducing agents, the use of organic salts as N-formylation catalysts, their physical properties required for high catalytic activity and their role in the catalytic ...

EPFL2019

Local structural investigation of hafnia-zirconia polymorphs in powders and thin films by X-ray absorption spectroscopy

Reinis Ignatans

Despite increasing attention for the recently found ferro- and antiferroelectric properties, the polymorphism in hafnia- and zirconia-based thin films is still not sufficiently understood. In the present work, we show that it is important to have a good qu ...

PERGAMON-ELSEVIER SCIENCE LTD2019

Photoredox-Catalyzed Decarboxylation for the Transfer of Alkynes and Nitriles Using Hypervalent Iodine Reagents

Franck Le Vaillant

Aliphatic alkynes and nitriles are privileged motifs in organic chemistry. Therefore, alkynes and nitriles have played a central role for the exploration and development of novel strategies to forge C-C bonds in efficient manner. They are broadly used as v ...

EPFL2019