Publications associées à Alkynyl Triazenes as Fluoroalkyne Surrogates: Regioselective Access to 4-Fluoro-2-pyridones by a Rh(III)-Catalyzed C–H Activation–Lossen Rearrangement–Wallach Reaction

Arylative Ring Expansion of 3-Vinylazetidin-3-Ols and 3-Vinyloxetan-3-Ols to Dihydrofurans by Dual Palladium and Acid Catalysis

In contrast to the well-studied 1-vinylcyclobu- tanols, the reactivity of 3-vinylazetidin-3-ols 1 and 3- vinyloxetan-3-ols 2 under transition metal catalysis remains largely unexplored. We report herein their unique reactivity under dual palladium and acid ...

Wiley-VCH Verlag GmbH2024

Hypervalent Iodine: New Reagents and Functionalization of Peptides

Eliott Hugo Joran Le Du

Alkynes are found in a multitude of natural or synthetic bioactive compounds. In addition to the capacity of these chemical motifs to impact the physicochemical properties of a molecule of interest, the well-established reactivity of alkynes makes them ide ...

EPFL2023

Separable Brønsted acidic imidazolium salts for polysaccharide hydrolysis in water

Kedar Ashok Abhyankar

The current reliance on limited petrochemical resources and the resulting ecological outcomes have made the exploration of alternative chemical and energy feedstocks invaluable. As such, the development of sustainable processes with a less harmful total en ...

EPFL2023

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

Exploring Photoredox-Catalyzed (Re)functionalizations with Core-Modified Benziodoxolones

Jérôme Waser, Franck Le Vaillant, Stephanie Grace Elizabeth Amos

Alkynes and nitriles are valuable building blocks in organic synthesis and also have multiple applications in chemical biology and materials science. Due to the high availability of tertiary alcohols, developing methods for their conversion into alkynes an ...

2022

Palladium-Catalyzed trans-Hydroalkoxylation: Counterintuitive Use of an Aryl Iodide Additive to Promote C-H Bond Formation

Jérôme Waser, Ashis Kumar Das, Luca Buzzetti, Mikus Purins

We report an enantioselective palladium-catalyzed trans-hydroalkoxylation of propargylic amines with a trifluoroacetaldehydederived tether to build chiral oxazolidines. Diastereoselective hydrogenation using a heterogeneous palladium catalyst then gave acc ...

2022

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

Asymmetric azide-alkyne Huisgen cycloaddition on chiral metal surfaces

Harald Brune, Roland Widmer, Roland Hany, Michael Bauer, Samuel Thomas Stolz

Achieving fundamental understanding of enantioselective heterogeneous synthesis is marred by the permanent presence of multitudinous arrangements of catalytically active sites in real catalysts. In this study, we address this issue by using structurally co ...

NATURE RESEARCH2021

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

Functionalization of remote C(sp3)-H bonds enabled by copper-catalyzed coupling of O-acyloximes with terminal alkynes

Qian Wang, Jieping Zhu, Ruben Omar Torres Ochoa, Zhaodong Li

Transition metal catalyzed Sonogashira cross-coupling of terminal alkynes with aryl(vinyl) (pseudo)halides has been successfully extended to alkyl halides for the synthesis of functionalized internal alkynes. The direct alkynylation of remote unfunctionali ...

Nature Research2020

Mechanistic Studies of Two Ni-Catalyzed Reactions: Reductive Amidation of Esters with Nitroarenes and Hydrosilylation of Alkenes

Marten Leendert Ploeger

Mechanistic investigations into homogeneously catalyzed reactions are essential for the fur-ther development of synthetic methodologies. Insights in the overall reaction pathway and vital steps such as the rate-determining and selectivity-determining steps ...

EPFL2020

Mechanisms of the Heterogeneously Catalyzed Reaction of CO2 Hydrogenation on Transition Metal Surfaces

Kun Zhao

Renewable energy supply and energy storage in a closed materials cycle are the urgent global challenges of the 21st century. Carbon dioxide (CO2) hydrogenation over catalysts is a method to produce synthetic fuels from renewable energy in a CO2 neutral cyc ...

EPFL2020

Exploitation of Unconventional Electrophiles in Enantioselective Pd(0)-Catalyzed C-H Functionalizations

Nicolai Cramer, Daria Grosheva

Asymmetric metal-catalyzed C-H functionalization is a powerful strategy for the rapid generation of complex target molecules from simple precursors. While aryl (pseudo) halides have been used as electrophilic substrates in enantioselective Pd(0)-catalyzed ...

2019

The dilemma between acid and base catalysis in the synthesis of benzimidazole from o-phenylenediamine and carbon dioxide

Paul Joseph Dyson, Martin Hulla, Simon Nussbaum, Alexy Robert Bonnin

The tandem synthesis of benzimidazole and other azoles can be achived by the N-formylation of ortho-substituted anilines followed by a cyclization reaction. However, CO2-based N-formylations with hydrosilane reducing agents are base catalyzed whereas the c ...

Royal Society of Chemistry2019

Delineation of the Critical Parameters of Salt Catalysts in the N-Formylation of Amines with CO2

Paul Joseph Dyson, Daniel Ortiz Trujillo, Dmitry Vasilyev, Martin Hulla

N-formylation of amines with CO2 is base-catalyzed and studies of salt catalysts reveal that the reaction is efficiently catalyzed by "free" floating anions of high basicity, as represented in the cover image. More information can be found in the Full Pape ...

WILEY-V C H VERLAG GMBH2019

Mechanochemistry-assisted hydrolysis of softwood over stable sulfonated carbon catalysts in a semi-batch process

Frédéric Vogel, Oliver Kröcher, David Ferdinand Scholz

The hydrolysis of lignocellulose is the first step in saccharide based bio-refining. The recovery of homogeneous acid catalysts imposes great challenges to the feasibility of conventional hydrolysis processes. Herein, we report a strategy to overcome these ...

2019

One-step access to N-enoxyimides by gold-catalysed addition of N-hydroxyimides to terminal alkynes

Nicolai Cramer, Coralie Danielle Annick Duchemin

N-Enoxyimides have become attractive substrates for novel catalytic transformations, yet their tedious multi-step synthesis hampers full exploitation of their synthetic potential. We report a gold(I)-catalyzed protocol to access N-enoxyimides from simple a ...

2019

Production, characterization and upgrading of biomass-derived acetal-stabilized carbohydrates

Ydna Marie Questell-Santiago

Biomass is an attractive source of renewable carbon-based fuels and chemicals. Multiple research efforts are centered around integrated biorefineries, where all fractions of biomass are converted to fuels or chemical products. These efforts are focused aro ...

EPFL2019

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

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

Construction of Phosphorus and Sulfur Stereogenic Centers by Chiral Cyclopentadienyl Rhodium(III) Catalysis

Yang Sun

Phosphorus- and sulfur-stereogenic compounds are widely used as ligands in asymmetric transition-metal catalysis and as organocatalysts. These molecules also show a large potential for pharmaceutical and agricultural use. However, synthesizing them in a st ...

EPFL2019