Publications associées à Alkyne trimerisation

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

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

Isolation, Characterisation and Reactivity of N-Heterocyclic Diazoolefins

Paul Varava

Examples for applications of nitrous oxide in organic synthesis remain rare up until today. First mayor contributions of our group were published in 2012, when nitrous oxide was successfully captured by N-heterocyclic carbenes. Subsequent studies investiga ...

EPFL2022

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

Anhydrous Conditions Enable the Catalyst-Free Carboxylation of Aromatic Alkynes with CO2 under Mild Conditions

Paul Joseph Dyson, Marinella Mazzanti, Felix Daniel Bobbink, Davide Toniolo

The direct carboxylation of aromatic alkynes with CO2, a cheap and widely available C1 source, is the most attractive method for the synthesis of carboxylic acids. Here we show that direct carboxylation of terminal alkynes can be simply performed in near-q ...

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

Divergent Synthesis of Densely Substituted Arenes and Pyridines via Cyclotrimerization Reactions of Alkynyl Triazenes

Kay Severin, Nicolai Cramer, Carl Thomas Bormann, Florian Gérald Abela, Jin Fay Tan, Frederick Mark Chadwick

Densely substituted fused aromatic triazenes can be prepared by [2 + 2 + 2] cyclotrimerization reactions of 1-alkynyl triazenes. The Cp*Ru-catalyzed cyclization proceeds well with both simple alkynyl triazenes and tethered 1-diynyl triazenes. Attractively, ...

2019

Chiral Cyclopentadienyl Cobalt(III) Complexes Enable Highly Enantioselective 3d-Metal-Catalyzed C-H Functionalizations

Nicolai Cramer, Yun-Suk Jang, Kristers Ozols

The synthesis of a set of cobalt(III)-complexes equipped with trisubstituted chiral cyclopentadienyl ligands is reported, and their steric and electronic parameters are mapped. The application potential of these complexes for asymmetric C-H functionalizati ...

2019

In situ tether formation from amines and alcohols enabling highly selective Tsuji-Trost allylation and olefin functionalization

Jérôme Waser, Ugo Jonathan Orcel

The use of tethers allows to overcome reactivity and selectivity issues often encountered with intermolecular reactions. Although tethers have been successfully applied for decades, their installation and removal usually requires additional steps. This min ...

2017

Palladium-Catalyzed Three-Component Reaction of Propargyl Carbonates, Isocyanides, and Alcohols or Water: Switchable Synthesis of Pyrroles and Its Bicyclic Analogues

Qian Wang, Jieping Zhu, Guanyinsheng Qiu

In the presence of a catalytic amount of Pd(OAc)2 and a stoichiometric amount of tert-butylamine, the reaction of propargyl carbonates, isocyanides, and alcohols afforded polysubstituted aminopyrroles in good yields. Using water as a nucleophile instead of ...

American Chemical Society2017

Synthesis and structure-activity relationship of 2,6-disubstituted pyridine derivatives as inhibitors of beta-amyloid-42 aggregation

Andrea Pfeifer, Andreas Muhs, Paolo Paganetti

It is assumed that amyloid-beta aggregation is a crucial event in the pathogenesis of Alzheimer's disease. Novel 2,6-disubstituted pyridine derivatives were designed to interact with the beta-sheet conformation of A beta via donor-acceptor-donor hydrogen b ...

Pergamon-Elsevier Science Ltd2016

Access to Chiral Cyclopentane Scaffolds by Enantioselective Nickel-Catalyzed Annulations

Joachim Sven Ernst Ahlin

The cyclopentane scaffold has attracted much attention due to its ubiquity in numerous bioactive natural products such as prostaglandins and polyquinanes. However, despite a plethora of available procedures to access this motif, a lack of methods that riva ...

EPFL2016

Rh(III)-Catalyzed C-H Functionalizations as Strategies for Versatile Organic Building Blocks

Van Manh Pham

Transition-metal catalyzed C-H functionalizations have impacted and changed synthetic approaches towards the construction of relevant complex molecules, comprising natural products, active pharmaceutical ingredients, and organic materials. This thesis desc ...

EPFL2016

2-(Methoxycarbonyl)ethyl as a Removable N-Protecting Group: Synthesis of Indoloisoquinolinones by Pd(II)-Catalyzed Intramolecular Diamination of Alkynes

Qian Wang, Jieping Zhu, Bo Yao, Minh Tu Ha

Pd(II)-catalyzed double cyclization of 1,2-diarylethynes bearing an N-methyl-N-[2-(methoxycarbonyl)ethyl]amino and an aminocarbonyl group at the ortho positions of the two aromatic rings afforded the tetracyclic N-[2-(methoxycarbonyl)-ethyl]indoloisoquinol ...

Amer Chemical Soc2015

Rational Catalyst Design for Selective Hydrogenations : Nitroarenes and Alkynes as Case Studies

Daniel André Samuel Lamey

Catalyst design for selective hydrogenations is of major importance for the manufacturing of fine chemicals. Catalytic procedure which uses scarce and expensive noble metals is very challenging in terms of exclusive attack of a single functionality or subs ...

EPFL2015

Synthesis of diverse di- to penta-substituted 1,2-dihydropyridine derivatives from gold(I)-catalyzed intramolecular addition of tertiary enamides to alkynes

Jieping Zhu

As 3-aza-1,5-enynes, internal and terminal alkyne-bearing tertiary enamides underwent an efficient Au(I)-catalyzed 6-endo-dig cyclization reaction to afford a variety of di- to penta-substituted 1,2-dihydropyridine derivatives in high yields. The cyclizati ...

Elsevier2015

Three-Component Povarov Reaction–Heteroannulation with Arynes: Synthesis of 5,6-Dihydroindolo[1,2‑a]quinolines

Qian Wang, Jieping Zhu, Ala Bunescu

A reaction of 2-acyl substituted tetrahydroquinolines, prepared by Lewis acid-catalyzed three-component reaction of α-oxo aldehydes, anilines, and dienophiles, with in situ generated arynes afforded 5,6-dihydroindolo[1,2-a]- quinolines in good to excellent ...

Amer Chemical Soc2014

Nickel(0)-Catalyzed Enantioselective Annulations of Alkynes and Arylenoates Enabled by a Chiral NHC Ligand: Efficient Access to Cyclopentenones

Nicolai Cramer, Pavel Alexandrovich Donets, Joachim Sven Ernst Ahlin

Cyclopentenones are versatile structural motifs of natural products as well as reactive synthetic intermediates. The nickel-catalyzed reductive [3+2] cycloaddition of alpha,beta-unsaturated aromatic esters and alkynes constitutes an efficient method for th ...

Wiley-Blackwell2014

Aromatic Homologation by Non- Chelate- Assisted RhIII- Catalyzed C -H Functionalization of Arenes with Alkynes

Nicolai Cramer, Van Manh Pham

Larger condensed arenes are of interest owing to their electro- and photochemical properties. An efficient synthesis is the catalyzed aromatic annulation of a smaller arene with two alkyne molecules. Besides difunctionalized starting materials, directed CH ...

Wiley-VCH Verlag GmbH2014

Chiral Cp-Rhodium(III)-Catalyzed Asymmetric Hydroarylations of 1,1-Disubstituted Alkenes

Nicolai Cramer, Baihua Ye, Pavel Alexandrovich Donets

Metal-catalyzed functionalizations at the ortho position of a directing group have become an efficient bond-forming strategy. A wide range of transformations that employ Cp*Rh-III catalysts have been described, but despite their synthetic potential, enanti ...

Wiley-VCH Verlag GmbH2014