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

Ring-Opening Reactions of Aminocyclopropanes and Aminocyclobutanes

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

Reactions of amines with ozone and chlorine: Two novel oxidative methods to evaluate the N-DBP formation potential from dissolved organic nitrogen

Karim-Alexandre Essaied, Urs von Gunten, Lucy Victoria Brown

The composition of oxidant-reactive dissolved organic nitrogen (DON) is poorly characterized, although its ozonation is likely to form a great variety of disinfection by-products containing a nitrogen-oxygen bond (NDBPs). In this study, two chemical oxidat ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Enhanced Treatment of Municipal Wastewater Effluents by Fe-TAML/H2O2: Efficiency of Micropollutant Abatement

Urs von Gunten

Combining iron with a tetraamido-macrocyclic ligand (Fe-TAML) as a catalyst and with hydrogen peroxide (H2O2) as the bulk oxidant is a process that has been suggested for the oxidative abatement of micropollutants during water treatment. In this study, the ...

AMER CHEMICAL SOC2021

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

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

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

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

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

Mechanistic Study of the N-Formylation of Amines with Carbon Dioxide and Hydrosilanes

Gabor Laurenczy, Paul Joseph Dyson, Martin Hulla

N-formylation of amines with CO2 and hydrosilane reducing agents proceeds via fast and complex chemical equilibria, which hinder easy analysis of the reaction pathways. In situ reaction monitoring and kinetic studies reveal that three proposed pathways, vi ...

2018

Protection Group Effects During α,γ-Diol Lignin Stabilization Promote High-Selectivity Monomer Production

Jeremy Luterbacher, Christopher Marc Hunston, Masoud Talebi Amiri, Wu Lan

Protection groups were introduced during biomass pretreatment to stabilize lignin's α,γ-diol group during its extraction and prevent its condensation. Acetaldehyde and propionaldehyde stabilized the α,γ-diol without any aromatic ring alkylation, which sign ...

Wiley-VCH Verlag GmbH2018

Dearomatization of electron poor six-membered N-heterocycles through [3+2] annulation with aminocyclopropanes

Jérôme Waser, Shyamal Chakrabarty, Johannes Preindl

Many abundant and highly bioactive natural alkaloids contain an indolizidine skeleton. A simple, high yielding method to synthesize this scaffold from N-heterocycles was developed. A wide range of pyridines, quinolines and isoquinolines reacted with donor- ...

2017

Organocatalysis: Fundamentals and Comparisons to Metal and Enzyme Catalysis

Pierre Vogel

Catalysis fulfills the promise that high-yielding chemical transformations will require little energy and produce no toxic waste. This message is carried by the study of the evolution of molecular catalysis of some of the most important reactions in organi ...

2016

Carbon Dioxide Based N-Formylation of Amines Catalyzed by Fluoride and Hydroxide Anions

Paul Joseph Dyson, Felix Daniel Bobbink, Shoubhik Das, Martin Hulla

We described herein a simple approach for N-formylation with CO2 and hydrosilane reducing agents. Fluoride and hydroxide salts efficiently catalyzed the reaction, principally through activation of the hydrosilanes, which led to hydrosilane reactivities com ...

Wiley-VCH Verlag2016

Mild synthesis of mercaptonitriles from vinyl nitriles and their cyclization reactions

Frank Nüesch, Antonia Neels

Thiol-ene addition of thioacetic acid A is widely used in the synthesis of thiols from vinyl precursors, but so far has not been conducted on non-conjugated vinyl nitriles. The challenge when vinyl nitriles are used is to selectively conduct the thiol-ene ...

Royal Soc Chemistry2016

Synthesis of diverse di- to penta-substituted 1,2-dihydropyridine derivatives from gold(I)-catalyzed intramolecular addition of tertiary enamides to alkynes

Jieping Zhu

As 3-aza-1,5-enynes, internal and terminal alkyne-bearing tertiary enamides underwent an efficient Au(I)-catalyzed 6-endo-dig cyclization reaction to afford a variety of di- to penta-substituted 1,2-dihydropyridine derivatives in high yields. The cyclizati ...

Elsevier2015

NIS-Assisted Aza-Friedel-Crafts Reaction with α-Carbamoysulfides as Precursors of

Nicolas George, Jieping Zhu

A general and practical N-iodosuccinimide (NIS)-promoted aza-Friedel–Crafts reaction of various aromatic nucleophiles with N-acylimines generated in situ from a-amidosulfides to give a rapid access to highly functionalized amines is described. The newly de ...

Wiley-Blackwell2014

Aqueous Oxidation of Sulfonamide Antibiotics: Aromatic Nucleophilic Substitution of an Aniline Radical Cation

Jeremy Samuel Arey, Peter Rudolf Tentscher

Sulfonamide antibiotics are an important class of organic micropollutants in the aquatic environment. For several, sulfur dioxide extrusion products have been previously reported upon photochemical or dark oxidation. Using quantum chemical modeling calcula ...

2013

Synthesis of 4-amino-1,2,3,4-tetrahydropyridine derivatives by intramolecular nucleophilic addition of tertiary enamides to in-situ generated imines

Jieping Zhu, Shuo Tong, Xu Yang

The reactivity of stable tertiary enamides in nucleophilic addition reaction with various in-situ generated imines was explored. Under very mild conditions, formyl-bearing tertiary enamides reacted with both aromatic and aliphatic amines to form imine inte ...

Elsevier2012

Kinetic and Mechanistic Investigations of the Oxidation of Tramadol by Ferrate and Ozone

Urs von Gunten, Saskia Gisela Zimmermann-Steffens

The kinetics and oxidation products (OPs) of tramadol (TRA), an opioid, were investigated for its oxidation with ferrate (Fe(VI)) and ozone (O-3). The kinetics could be explained by the speciation of the tertiary amine moiety of TRA, with apparent second-o ...

2012

Synthesis of Hydroxylated 3,4-Dihydropyridine-2-ones from Intramolecular Nucleophilic Addition Reaction of Oxirane-containing Tertiary Enamides

Jieping Zhu, Shuo Tong

Catalyzed by p-toluenesulfonic acid in dry acetonitrile, oxirane-containing tertiary enamides underwent efficient cyclization via intramolecular addition to produce 3-hydroxy-3,4-dihydropyridin-2(1H)-one derivatives in moderate to good yields. ...

Georg Thieme Verlag2011