Publications associées à Énol

Toward Superior Hydroisomerization Catalysts through Thermodynamic Optimization

The need to reduce the lifecycle greenhouse gas emissions of fuels and lubricants has renewed interest in hydroisomerization processes. Here it is shown how recognizing the signature of individual alkane hydrocracking pathways enables delineating changes t ...

AMER CHEMICAL SOC2023

TiCl3-Mediated Reductive Cyclization of Tetrasubstituted Alkenes and Enol Esters Bearing a 2-Nitrophenyl Substituent

Dina Boyarskaya

Indole is one of the most important heterocycles widely present in bioactive natural products, pharmaceuticals, agrochemicals and materials. Being easily accessible, the 2-nitrostyrenes are attractive starting materials for the indole synthesis and the Cad ...

EPFL2023

Development of Hetero-Vinylbenziodoxolone Reagents for Applications in Synthetic Methodology and Biomolecule Functionalization

Nina Declas

Among the numerous existing chemical motifs, alkenes, alkynes, enol ethers and enamides, with an unsaturated carbon-carbon bond, are versatile functional groups that are found in many natural products and bioactive compounds. They are widely used as valuab ...

EPFL2023

Synthesis of 3-Acyloxyindolenines by TiCl3-Mediated Reductive Cyclization of 2-(ortho-Nitroaryl)-Substituted Enol Esters

Qian Wang, Jieping Zhu, Cyril Piemontesi, Dina Boyarskaya, Alberto Ongaro

In the presence of TiCl3, the reductive cyclization of tetrasubstituted enol esters bearing a 2-(ortho-nitroaryl) substituent affords 3-acyloxy-2,3-disubstituted indolenines in good yields. A domino process involving the partial reduction of nitro to a nit ...

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

Catalytic enantioselective Pictet-Spengler reaction of carbonyl compounds: Development and application to the asymmetric total synthesis of indole alkaloids

Rémi Julien Sylvain Andres

This thesis consists in an extensive study about the enantioselective Pictet-Spengler reaction (EPSR) and its application to the total synthesis of monoterpene indole alkaloids (MIAs). The general introduction presents the literature background about this ...

EPFL2022

Construction of Functional Superhydrophobic Biochars as Hydrogen Transfer Catalysts for Dehydrogenation of N-Heterocycles

Zhaowen Dong, Feng Zhou

To endow metal-free materials with the high catalytic activity that is typically featured by a metal-based catalyst is yet a constant pursuit in the field of catalytic chemistry. In this work, novel functional biochars (DCNs) were prepared from wheat straw ...

AMER CHEMICAL SOC2021

Triazene-Activated Donor–Acceptor Cyclopropanes: Ring-Opening and (3 + 2) Annulation Reactions

Rosario Scopelliti, Kay Severin, Jérôme Waser, Farzaneh Fadaei Tirani, Abdusalom Suleymanov, Zhaowen Dong, Bastian Antoine Rodolphe Claude Muriel, Eliott Hugo Joran Le Du

Donor–acceptor cyclopropanes substituted with 3,3-dialkyltriazenyl groups are described herein. The strong electron-donating character of the triazene renders the cyclopropanes highly reactive, allowing for catalyst-free ring-opening reactions with methano ...

2020

Photocatalytic Umpolung of N- and O-substituted alkenes for the synthesis of 1,2-amino alcohols and diols

Jérôme Waser, Stefano Nicolai, Stephanie Grace Elizabeth Amos

We report an organophotocatalytic 1,2-oxyalkynylation of ene-carbamates and enol ethers using Ethynyl BenziodoXolones (EBXs). 1-Alkynyl-1,2-amino alcohols and diols were obtained in up to 89% yield. Photocatalytic formation of radical cations led to Umpolu ...

2020

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

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

Development of New Strategies of Umpolung with Cyclic Hypervalent Iodine Reagents

Paola Caramenti

Organic chemistry is essential for the development of a modern society and technical progress requires the continuous development of synthetic methodologies Novel, efficient, selective and flexible protocols are employed to access complex frameworks from s ...

EPFL2019

Stereoselective synthesis of alkyl-, aryl-, vinyl- and alkynyl-substituted Z-enamides and enol ethers

Jérôme Waser, Matthew Wodrich, Paola Caramenti, Romain Gaëtan Tessier, Nina Declas

Enamides and enol ethers are valuable building blocks in synthetic chemistry, yet their stereoselective synthesis can be challenging. Herein, we report a new stereoselective synthesis of vinyl, aryl, alkynyl, alkyl and thio-substituted Z-enamides and enol ...

2019

Total Synthesis of Alstilobanine C, Undulifoline and Alstilobanine B

Nicolas David Gaeng

The total synthesis of pentacyclic monoterpene indole alkaloids is the focus of this thesis. Total syntheses of (±)-alstilobanine C, (±)-undulifoline and (±)-alstilobanine B, three natural products from the Ulean family of alkaloids, were accomplished. The ...

EPFL2018

Synthesis of Adamantane Aminoethers with Antitubercular Potential

Stewart Cole, Anthony Vocat

Background: Intrigued by the fact that aminoadamantane derivatives, bearing the active 1,2-ethylenediamine moiety, are promising antitubercular agents, we report herein the synthesis and the antitubercular evaluation of N,N'-substituded-4,4'-[adamantane-2, ...

Bentham Science Publ Ltd2017

A Water-Bridged H-Bonding Network Contributes to the Catalysis of the SAM-Dependent C-Methyltransferase HcgC

Xile Hu, Tao Xu, Lichen Bai

[Fe]-hydrogenase hosts an iron-guanylylpyridinol (FeGP) cofactor. The FeGP cofactor contains a pyridinol ring substituted with GMP, two methyl groups, and an acylmethyl group. HcgC, an enzyme involved in FeGP biosynthesis, catalyzes methyl transfer from S- ...

Wiley-VCH Verlag GmbH2017

Kinetically Trapped Liquid-State Conformers of a Sodiated Model Peptide Observed in the Gas Phase

Thomas Rizzo, Markus Schneider, Chiara Masellis, Carsten Baldauf

We investigate the peptide AcPheAla(5)Lyar(+), a model system for studying helix formation in the gas phase, in order to fully understand the forces that stabilize the helical structure. In particular, we address the question of whether the local fixation ...

2017

Organocatalytic Enantioselective Vinylogous Pinacol Rearrangement Enabled by Chiral Ion Pairing

Qian Wang, Jieping Zhu, Hua Wu

An enantioselective pinacol rearrangement of functionalized (E)-2-butene-1,4-diols was developed. In the presence of a catalytic amount of a chiral BINOL-derived N-triflyl phosphoramide, these 1,4-diols rearranged to b,g-unsaturated ketones in excellent yi ...

Wiley-Blackwell2016

Gas-phase probes of kinetically trapped peptides

Liudmila Voronina

Gas-phase techniques are promising for studying intrinsically disordered peptides and proteins, as they can be implemented in a conformer-selective way. One of the issues that prevent them from finding a broader use is the question of to which extent the s ...

EPFL2016

Conformations of prolyl-peptide bonds in the bradykinin 1-5 fragment in solution and in the gas phase

Thomas Rizzo, Antoine Louis Claude Masson, Michael Zachary Kamrath, Liudmila Voronina, Carsten Baldauf

The dynamic nature of intrinsically disordered peptides makes them a challenge to characterize by solution-phase techniques. In order to gain insight into the relation between the disordered state and the environment, we explore the conformational space of ...

Amer Chemical Soc2016