Publications associées à Ester

Organic Dye Photocatalyzed Synthesis of Functionalized Lactones and Lactams via a Cyclization-Alkynylation Cascade

An organic dye photocatalyzed lactonization-alkynylation of easily accessible homoallylic cesium oxalates using ethynylbenziodoxolone (EBX) reagents has been developed. The reaction gave access to valuable functionalized lactones and lactams in up to 88% y ...

2024

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

New Polymers from Biomass-Derived Hydroxycinnamic Acid Derivatives

Ghezae Tekleab

Polymers play a central role in shaping our world across various fields, but their heavy reliance on petrochemicals poses climate change, environmental and health risks. To address and alleviate these issues, transitioning to sustainable polymers, sourced ...

EPFL2024

Synthesis and application of bifunctional hypervalent iodine reagents for peptide modification

Elija Grinhagena

Protein-protein interactions (PPIs) are responsible for regulating many biological processes in human bodies. PPIs often have a large binding site and often interact through an alpha helical segment. Therefore, the inhibition of PPIs can be difficult using ...

EPFL2023

Organocatalytic Enantioselective Pictet–Spengler Reaction of α‐Ketoesters: Development and Application to the Total Synthesis of (+)‐Alstratine A

Qian Wang, Jieping Zhu, Rémi Julien Sylvain Andres, Fenggang Sun

We report herein an asymmetric Pictet– Spengler reaction of α-ketoesters. In the presence of a catalytic amount of simple alanine-derived squaramide and p-nitrobenzoic acid, reaction of tryptamines with methyl 2-oxoalkanoates afforded the corresponding 1- ...

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

Cysteine-Cysteine Cross-Conjugation of both Peptides and Proteins with a Bifunctional Hypervalent Iodine-Electrophilic Reagent

Jérôme Waser, Stefano Nicolai, Abhaya Kumar Mishra

Peptide and protein bioconjugation sees ever-growing applications in the pharmaceutical sector. Novel strategies and reagents that can address the chemo- and regioselectivity issues inherent to these biomolecules, while delivering stable and functionalizab ...

2023

Zinc carboxylate optimization strategy for extending Al-air battery system's lifetime

Andreas Züttel, Thi Ha My Pham, Liping Zhong, Manhui Wei

Although Al-air batteries are expected to be the candidates for energy conversion systems in renewable energy market due to the higher energy density, richer reserves, and lighter mass of Al metal, the anode self-discharge is seen as a notorious issue that ...

ELSEVIER SCI LTD2023

Simultaneous Generation of Methyl Esters and CO in Lignin Transformation

Paul Joseph Dyson, Mingyang Liu

Lignin is an abundant renewable carbon source. Due to its complex structure, utilization of lignin is very challenging. Herein, we describe an efficient strategy for the simultaneous utilization of lignin, in which the methoxy groups in lignin react with c ...

Wiley-VCH Verlag GmbH2022

Investigation of Carboxylic Acid Isosteres and Prodrugs for Inhibition of the Human SIRT5 Lysine Deacylase Enzyme

Alexander Lund Nielsen

Sirtuin 5 (SIRT5) is a protein lysine deacylase enzyme that regulates diverse biology by hydrolyzing epsilon-N-carboxyacyllysine posttranslational modifications in the cell. Inhibition of SIRT5 has been linked to potential treatment of several cancers but ...

Wiley-VCH Verlag GmbH2022

Engineering of chitosan-based derivatives for non-viral gene delivery

Laura Camille Louise Nicolle

Gene therapy offers the possibility to treat or even cure diseases originating from genetic defects by introducing a therapeutic gene in target cells or correcting the initial defective gene. Amongst different options, non-viral vectors rely on the deliver ...

EPFL2022

Standard-Free Quantification of Dicarboxylic Acids: Case Studies with Salt-Rich Effluents and Serum

Christian Ludwig, Daniil Salionov, Sasa Bjelic

The present study evaluates the ionization efficiency (IE) of linear and branched C2–C14 dicarboxylic acids (DCAs) by electrospray ionization (ESI) under different conditions. The influence of the concentration of organic modifier (MeOH); mobile phase addi ...

2022

Cys-Cys and Cys-Lys Stapling of Unprotected Peptides Enabled by Hypervalent Iodine Reagents

Jérôme Waser, Christian Heinis, Gontran Sangouard, Elija Grinhagena

Easy access to a wide range of structurally diverse stapled peptides is crucial for the development of inhibitors of protein-protein interactions. Herein, we report bis-functional hypervalent iodine reagents for two-component cysteine-cysteine and cysteine ...

Wiley-VCH Verlag GmbH2021

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

Xile Hu, Lara Lavrencic, Runze Mao, Xiangli Yi

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

Three-membered cyclic digermylenes stabilised by an N-heterocyclic carbene dagger

Zhaowen Dong

Treatment of potassium salts of silole dianions with donor stabilised germanium dichlorides gave the anticipated silagermafulvenylidenes R2Si = Ge(Do) (R2Si = 1-silacyclopentadiendiyl, Do = N-heterocyclic carbene (NHC)) only as transient intermediates in a ...

2021

Method Development towards Orthogonal Electrophile Delivery

Lingxi Wang

Redox signaling events mediated by reactive electrophilic species (RES) are key players in several cellular processes. However, the studies on RES have been challenging due to their high reactivity towards numerous nucleophilic groups present in the cells ...

EPFL2021

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

Catalytic (3+2) annulation of donor-acceptor aminocyclopropane monoesters and indoles

Jérôme Waser, Vincent Géry C Pirenne, Emma Gabrielle Louise Robert

The efficient catalytic activation of donor-acceptor aminocyclopropanes lacking the commonly used diester acceptor is reported here in a (3 + 2) dearomative annulation with indoles. Bench-stable tosyl-protected aminocyclopropyl esters were converted into c ...

2021

Printed Polymer Composite Sensors for Low-Power, Near Room-Temperature Detection and Classification of VOCS

Jürgen Brugger, Thomas Maeder, Mohammadmahdi Kiaee

We demonstrate the application of inkjet-printed near room-temperature chemiresistors composed of polymer-carbon black (CB) composites for detecting and classifying volatile organic compounds (VOC). Our results demonstrate that the printed sensors can sele ...

IEEE2021

1,3,2‐Diazaphospholenes Catalyze the Conjugate Reduction of Substituted Acrylic Acids

Nicolai Cramer, John Henry Reed

The potent nucleophilicity and remarkably low basicity of 1,3,2- diazaphospholenes (DAPs) is exploited in a catalytic, metal-free 1,4-reduction of free ,-unsaturated carboxylic acids. Notably, the reduction occurs without a prior deprotonation of the car ...

Wiley-VCH Verlag2020