Publications associées à Alkylation

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

High-Density Immobilization of TCEP on Silica Beads for Efficient Disulfide Reduction and Thiol Alkylation in Peptides

Christian Heinis

Tris-(2-carboxyethyl)phosphine (TCEP) linked to agarose beads is widely used for reducing disulfide bridges in proteins and peptides. The immobilization of TCEP on beads allows efficient removal after reduction to prevent its reaction with alkylating reage ...

2023

Monitoring On-Target Signaling Responses in Larval Zebrafish- Z-REX Unmasks Precise Mechanisms of Electrophilic Drugs and Metabolites

Yimon Aye, Jesse Poganik, Kuan-Ting Huang, Phillippe Ly

Reactive metabolites and related electrophilic drugs are among the most challenging small molecules to study. Conventional approaches to deconstruct the mode of action (MOA) of such molecules leverage bulk treatment of experimental specimens with an excess ...

JOURNAL OF VISUALIZED EXPERIMENTS2023

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

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

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

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

Mechanistic classification and benchmarking of polyolefin depolymerization over silica-alumina-based catalysts

Paul Joseph Dyson, Mounir Driss Mensi, Felix Daniel Bobbink, Antoine Philippe Van Muyden, Wei-Tse Lee, Jed Russell Carullo

Carbon-carbon bond cleavage mechanisms play a key role in the selective deconstruction of alkanes and polyolefins. Here, we show that the product distribution, which encompasses carbon range and formation of unsaturated and isomerization products, serves a ...

Nature Research2022

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

A Strategy to Conjugate Bioactive Fragments to Cytotoxic Diiron Bis(cyclopentadienyl) Complexes

Paul Joseph Dyson, Mouna Hadiji, Silvia Schoch, Sarah Alexandra Pais Pereira

A series of bioactive molecules were synthesized from the condensation of aspirin or chlorambucil with terminal alkynes bearing alcohol or amine substituents. Insertion of the resulting alkynes into the iron-carbyne bond of readily accessible diiron bis(cy ...

AMER CHEMICAL SOC2021

Atropo‐Enantioselective Oxidation‐Enabled Iridium(III)‐Catalyzed C−H Arylations with Aryl Boronic Esters

Nicolai Cramer

Atropo-enantioselective biaryl coupling through C−H bond functionalization is an emerging technology allowing direct construction of axially chiral molecules. This approach is largely limited to electrophilic coupling partners. We report a highly atropo-en ...

Wiley-VCH Verlag GmbH2021

Umpolung Of Electron-Rich Heteroarenes With Hypervalent Iodine Reagents

Jérôme Waser, Raj Kumar Nandi

Five-membered heterocycles are well known for their innate nucleophilicity. In contrast, reaction of these heterocycles as electrophiles is less established and has become only recently an intensively investigated research area in synthetic chemistry. The ...

PERGAMON-ELSEVIER SCIENCE LTD2021

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

Ruthenium on phosphorous-modified alumina as an effective and stable catalyst for catalytic transfer hydrogenation of furfural

Oliver Kröcher, Davide Ferri, Gaël Peng, Thibault Xavier Florian Fovanna

Supported ruthenium was used in the liquid phase catalytic transfer hydrogenation of furfural. To improve the stability of Ru against leaching, phosphorous was introduced on a Ru/Al2O3 based catalyst upon impregnation with ammonium hypophosphite followed b ...

2020

Partial Hydrogenation of 2-Methyl-3-butyn-2-ol over Pd/ZnO: Effect of Reduction Temperature on Alloy Formation and Catalytic Response

Lioubov Kiwi, Fernando Cardenas Lizana

We have investigated the catalytic effect of the beta-phase PdZn alloy on selective gas-phase hydrogenation of 2-methyl-3-butyn-2-ol over Pd/ZnO using Pd/Al2O3 as a benchmark. Activation (in H-2) of Pd/ZnO to 973 K generated a beta-phase PdZn alloy (from X ...

AMER CHEMICAL SOC2020

Enantioselective C(sp(3))-C(sp(3)) cross-coupling of non-activated alkyl electrophiles via nickel hydride catalysis

Xile Hu, Runze Mao, Srikrishna Bera

Cross-coupling of two alkyl fragments is an efficient method to produce organic molecules rich in sp(3)-hybridized carbon centres, which are attractive candidate compounds in drug discovery. Enantioselective C(sp(3))-C(sp(3)) coupling is challenging, espec ...

2020

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

Synthesis of heterogeneous catalysts with metal oxide overcoat for renewable catalysis applications

Yuan-Peng Du

Metal oxide deposition is an emerging synthetic technique for designing heterogeneous catalysts. Depositing a nanoscale overcoat of metal oxide on heterogeneous catalysts can modify their structural and chemical characteristics. Many deposition approaches, ...

EPFL2020

Post-synthesis deposition of mesoporous niobic acid with improved thermal stability by kinetically controlled sol–gel overcoating

Jeremy Luterbacher, Florent Emmanuel Héroguel, Yuan-Peng Du

Niobia is a well-known solid acid catalyst owing to its intrinsic Brønsted and Lewis acidity. However, catalyst development with this oxide has been limited by our ability to control its pore structure and thermal stability. Here we report a novel post-syn ...

Royal Society of Chemistry2019

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