Publications associées à Photochemical Functionalization of Heterocycles with EBX Reagents: C-H Alkynylation versus Deconstructive Ring Cleavage

Novel Alkynylation Methods through the Combination of Hypervalent Iodine Reagents and Alkynyl-trifluoroborate Salts

The alkyne motif is a versatile functional group often encountered in organic chemistry. It can be involved in various transformations such as the alkyne-azide cycloaddition and has found widespread application in medicinal chemistry, chemical biology and ...

EPFL2024

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

Qian Wang, Jieping Zhu, Takuji Fujii

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

Recent progress in alkynylation with hypervalent iodine reagents

Jérôme Waser, Eliott Hugo Joran Le Du

Although alkynes are one of the smallest functional groups, they are among the most versatile building blocks for organic chemistry, with applications ranging from biochemistry to material sciences. Alkynylation reactions have traditionally relied on the u ...

Royal Society of Chemistry2023

Synthesis and Applications of Ynimines and Enantioselective Total Synthesis of Artatrovirenol A

Rémi Hugo Lavernhe

The first chapter of this thesis describe the development of a general synthesis of ynimines, an under-exploited motif in organic chemistry. In the presence of an inexpensive copper catalyst and 2,2'-biquinoline, reaction of easily accessible O-acyloximes ...

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

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

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

Radical Alkynylations with EthynylBenziodoXolones: From Photocatalysis to Direct Excitation

Jérôme Waser, Stephanie Grace Elizabeth Amos

Ethynylbenziodoxolones (EBXs) have recently emerged as potent reagents for the alkynylation of radicals. Their combination with photocatalysis allows the synthesis of valuable alkynes at room temperature. Herein, we discuss two photomediated strategies for ...

2022

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

Direct Photoexcitation of Ethynylbenziodoxolones: An Alternative to Photocatalysis for Alkynylation Reactions**

Jérôme Waser, Franck Le Vaillant, Stephanie Grace Elizabeth Amos, Diana Cavalli

Ethynylbenziodoxolones (EBXs) are commonly used as radical traps in photocatalytic alkynylations. Herein, we report that aryl-substituted EBX reagents can be directly activated by visible light irradiation. They act as both oxidants and radical traps, alle ...

Wiley-VCH Verlag GmbH2021

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

Reactions of nitrogen-containing compounds with ozone: kinetics and mechanisms

Sung Eun Lim

Nitrogen-containing moieties are widespread in natural waters in dissolved organic nitrogen and micropollu-tants. They are often susceptible to an electrophilic attack of ozone because of the electron-rich nature of the neutral form of nitrogen in organic ...

EPFL2020

Azide Radical Initiated Ring Opening of Cyclopropenes Leading to Alkenyl Nitriles and Polycyclic Aromatic Compounds

Jérôme Waser, Bastian Antoine Rodolphe Claude Muriel

We report herein a radical‐mediated amination of cyclopropenes. The transformation proceeds through a cleavage of the three‐membered ring after the addition of an azide radical on the strained double bond and leads to tetrasubstituted alkenyl nitrile deriv ...

Wiley-VCH Verlag GmbH2020

Development of Photocatalysts towards the Visible-Light driven C-Terminal Bioconjugation of Peptides and Proteins

Marion Marie-Agnès Garreau

If small molecules have led to tremendous progress in curing diseases, new therapeutic agents such as peptides or antibody-drugs conjugates have emerged as a highly promising next generation of pharmaceuticals. As for small molecules, their derivatization ...

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

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

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

Alkynylation of radicals: spotlight on the "Third Way" to transfer triple bonds

Jérôme Waser, Franck Le Vaillant

The alkynylation of radical intermediates has been known since a long time, but had not been broadly applied in synthetic chemistry, in contrast to the alkynylation of either electrophiles or nucleophiles. In the last decade however, it has been intensivel ...

2019

Copper-Catalyzed Oxyalkynylation of C-S Bonds in Thiiranes and Thiethanes with Hypervalent Iodine Reagents

Jérôme Waser, Guillaume Dominique Pisella, Julien Aymeric Borrel

We report the oxyalkynylation of thiiranes and thietanes using ethynylbenziodoxolone reagents (EBXs) to readily access functionalized building blocks bearing an alkynyl, a benzoate, and an iodide group. The reaction proceeds with high atom efficiency most ...

2019

"Doubly Orthogonal" Labeling of Peptides and Proteins

Jérôme Waser, Nora Guidotti, Beat Fierz, Romain Gaëtan Tessier, Raphaël Michel Henri Simonet-Davin

Herein, we report a cysteine bioconjugation methodology for the introduction of hypervalent iodine compounds onto biomolecules. Ethynylbenziodoxolones (EBXs) engage thiols in small organic molecules and cysteine-containing peptides and proteins in a fast a ...

2019