Publications associées à Alcyne

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

Palladium‐Based Dyotropic Rearrangement Enables A Triple Functionalization of Gem‐Disubstituted Alkenes: An Unusual Fluorolactonization Reaction

Qian Wang, Jieping Zhu, Qiang Feng, Chenxu Liu

We report in this paper a Pd(II)-catalyzed migratory gem-fluorolactonization of ene-carboxylic acids. Reaction of 4-methylenealkanoic acid derivatives with Selectfluor in the presence of Pd(OAc)2 (1.0 mol %) at room temperature affords fluorolactones in go ...

Wiley-VCH Verlag GmbH2024

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

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 of propargyl silanes from terminal alkynes via a migratory Sonogashira reaction

Jérôme Waser, Mikus Purins, Lucas Antoine Théo Eichenberger

Herein we report a mild synthesis of propargyl silanes from terminal alkynes. We exploit a bromonaphthyl-substituted silane as a silylmethyl electrophile surrogate, which participates in a Sonogashira reaction after an aryl-to-alkyl Pd-migration. Twenty-se ...

Royal Society of Chemistry2023

Photocatalyzed [2σ + 2σ] and [2σ + 2π] Cycloadditions for the Synthesis of Bicyclo[3.1.1]heptanes and 5- or 6-Membered Carbocycles

Jérôme Waser, Matthew Wodrich, André Bossonnet

We report the use of photocatalysis for the homolytic ring-opening of carbonyl cyclopropanes. In contrast to previous studies, our approach does not require a metal cocatalyst or a strong reductant. The carbonyl cyclopropanes can be employed for both [2σ + ...

2023

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

Terminal Alkynes as One-Carbon Donors in [5+1] Heteroannulation: Synthesis of Pyridines via Ynimine Intermediates and Application in the Total Synthesis of Anibamine B

Qian Wang, Jieping Zhu, Rémi Hugo Lavernhe

Transition-metal-catalyzed [4+2] heteroannulation of alpha,beta-unsaturated oximes and their derivatives with alkynes has been developed into a powerful strategy for the synthesis of pyridines. It nevertheless lacks regioselectivity when unsymmetrically su ...

Wiley-VCH Verlag GmbH2023

Copper (I)‐BOX Catalyzed Asymmetric 3‐Component Reaction for the Synthesis of Trifluoromethylated Propargylic Ethers and Anilines**

Jérôme Waser, Nieves Pilar Ramirez Hernandez

An asymmetric 3-component reaction between EthynylBenziodoXoles (EBXs), 2,2,2-trifluorodiazoethane and nucleophiles catalyzed by a CuI-BOX (Bisoxazoline) catalyst is described. This protocol gives access to chiral trifluoromethylated propargyl ethers and a ...

Wiley-VCH Verlag GmbH2023

Synthesis, isolation and application of a sila-ketenyl anion

Rosario Scopelliti, Shiori Fujimori

Ynolates or ketenyl anions, [RCCO]-, are negatively charged reactive intermediates, which can be generated in situ and used for divergent chemical transformations. Ynolates can react either at the oxygen or carbon centres or across the C-C triple bond, mak ...

Springernature2023

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

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

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

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

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

Two-Carbon Ring Expansion of Cyclobutanols to Cyclohexenones Enabled by Indole Radical Cation Intermediate: Development and Application to a Total Synthesis of Uleine

Qian Wang, Jieping Zhu, Alexandre Julien Florent Leclair

A single-electron transfer (SET) oxidation of indole or benzo[b]thiophene to a radical cation reverses the intrinsic polarity of these pi-excessive bicyclic heteroarenes. Here we report an oxidative two-carbon homologation of cyclobutanols to cyclohexenone ...

AMER CHEMICAL SOC2022

Pd(II)-Catalyzed Aminoacetoxylation of Alkenes Via Tether Formation

Jérôme Waser, Stefano Nicolai, Ashis Kumar Das, Thomas Rossolini

A Pd-catalyzed method based on the use of a molecular tether is described for olefin difunctionalization. Enabled by an easily introduced trifluoroacetaldehyde-derived tether, a simultaneous introduction of oxygen and nitrogen heteroatoms across unsaturate ...

2022

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

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

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

Chemo- and regio-divergent access to fluorinated 1-alkyl and 1-acyl triazenes from alkynyl triazenes

Kay Severin, Nicolai Cramer, Carl Thomas Bormann, Jin Fay Tan

The 1,1,2,2-tetrafluoroethylene unit is prevalent in bioactive molecules and functional materials. Despite being in principle a straightforward strategy to access this motif, the direct tetrafluorination of alkynes involves very hazardous or inconvenient r ...

2022