Publications associées à Zinc-gold cooperative catalysis for the direct alkynylation of benzofurans

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

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

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 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

Tandem Hydroformylation-Aldol Condensation Reaction Enabled by Zn-MOF-74

Berend Smit, Daniele Ongari

The tandem hydroformylation-aldol condensation (tandem HF-AC) reaction offers an efficient synthetic route to the synthesis of industrially relevant products. The addition of Zn-MOF-74 to the cobalt-catalyzed hydroformylation of 1-hexene enables tandem HF- ...

WILEY-V C H VERLAG GMBH2023

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

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

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

Tosyloxybenziodoxolone: A Platform for Performing the Umpolung of Alkynes in One-Pot Transformations

Jérôme Waser, Julien Aymeric Borrel

Ethynylbenziodoxolones (EBXs) are commonly encountered reagents for the electrophilic alkynylation of nucleophiles. Herein, we report a one-pot, two-step process for EBX generation and their direct application in substrate functionalization. Our approach e ...

2021

New Vinylation and Alkynylation Strategies with Hypervalent Iodine Reagents and Diazo Compounds

Guillaume Dominique Pisella

The development of a sequential copper-catalyzed oxy-alkynylation/intramolecular [4+2] cycloaddition of allenes and arenes was investigated at first. This one-pot protocol allowed the construction of complex polycylic architectures with high efficiency fro ...

EPFL2021

Reduction of PdO/Al2O3 in Liquid Cyclohexane Followed In Situ by ATR-IR, High-Energy XRD, and XAS

Thibault Xavier Florian Fovanna, Oliver Kröcher, Davide Ferri

Supported Pd-based catalysts used in heterogeneously catalyzed liquid phase processes often undergo an activation step through reduction of the oxide phase or of the oxidic passivation layer prior to reaction. An oxidized Pd/Al2O3 catalyst was reduced by u ...

AMER CHEMICAL SOC2021

Propelling the hydrogen economy: from chemical storage and delivery to utilization in biomass conversion

Lu Chen

Since H2 is a non-polluting, inexhaustible, efficient, and sustainable energy carrier, it has been forecast to become one of the major carriers of energy in the future and is also essential in the production of feedstock chemicals derived from renewable ca ...

EPFL2021

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

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

Jérôme Waser, Marion Marie-Agnès Garreau

The development of novel methodologies for the functionalization of saturated heterocycles is highly desirable. Herein, we report a cheap and efficient photochemical method for the C-H functionalization of saturated O-heterocycles, as well as the deconstru ...

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

Iron-Catalyzed Reductive Coupling of Alkyl Iodides with Alkynes To Yield cis-Olefins: Mechanistic Insights from Computation

Xile Hu

In a recent study, a new procedure for Z-selective olefin synthesis by reductive coupling of alkyl iodides with terminal alkynes in the presence of iron salts is described. This transformation is representative of many newly developed synthetic routes thro ...

AMER CHEMICAL SOC2020