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Alkynylation

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Publications associées (32)

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

Enantioselective Rhodium-catalyzed C-C Bond Activation of Cyclobutanones

Nicolai Cramer, Laetitia Marie Mélanie Souillart

The activation of carbon-carbon bonds has attracted much attention in the past decade. Despite important progress, the development of asymmetric reactions lags behind. For the first time, asymmetric rhodium(I)-catalyzed direct oxidative additions into enan ...

Swiss Chemical Soc2015

Room temperature alkynylation of H-phosphi(na)tes and secondary phosphine oxides with ethynylbenziodoxolone (EBX) reagents

Jérôme Waser, Chia-Chun Chen

Highly efficient protocols for the alkynylation of H-phosphi(na)tes and secondary phosphine oxides with silyl, aryl and alkyl ethynyl-benziodoxolone (EBX) reagents are reported. Alkynyl phosphorus compounds were obtained in 69-93% yield without the need fo ...

Royal Society of Chemistry2014

Mild and Phosphine-Free Iron-Catalyzed Cross-Coupling of Nonactivated Secondary Alkyl Halides with Alkynyl Grignard Reagents

Xile Hu, Chi Wai Cheung, Peng Ren

A simple protocol for iron-catalyzed cross-coupling of nonactivated secondary alkyl bromides and iodides with alkynyl Grignard reagents at room temperature has been developed. A wide range of secondary alkyl halides and terminal alkynes are tolerated to af ...

American Chemical Society2014

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

Zinc-gold cooperative catalysis for the direct alkynylation of benzofurans

Jérôme Waser, Yifan Li

The direct alkynylation of benzofurans was achieved for the first time using the hypervalent iodine reagent 1-[(triisopropylsilyl)ethynyl]-1,2-benziodoxol-3(1H)-one (TIPS-EBX) based on the cooperative effect between a gold catalyst and a zinc Lewis acid. H ...

2013

C2-Selective Direct Alkynylation of Indoles

Jérôme Waser, Jonathan Brand, Gergely Laszlo Tolnai, Stephanie Ganss

The first C2-selective alkynylation of indoles using the hypervalent iodine reagent triisopropylsilylethyny1-1,2-benziodoxol-3(1H)-one (TIPS-EBX) with Pd(II) as a catalyst is described. This convenient and robust method gives a single-step access to substi ...

American Chemical Society2013

Para-Selective Gold-Catalyzed Direct Alkynylation of Anilines

Jérôme Waser, Jonathan Brand

A method for the para-selective alkynylation of anilines is reported using AuCl as catalyst and triisopropylsilylethynyl-1,2-benziodoxol-3(1H)-one (TIPS-EBX) as an electrophilic acetylene equivalent. Para-alkynyl anilines substituted at positions 2 or 3 we ...

American Chemical Society2012

Synthesis of 1-[(Triisopropylsilyl)ethynyl]-1 lambda(3),2-benziodoxol-3(1H)-one and Alkynylation of Indoles, Thiophenes, and Anilines

Jérôme Waser, Jonathan Brand

An efficient procedure was developed for the synthesis of 1-[(triisopropylsilyl)ethynyl]-1 lambda(3),2-benziodoxol-3(1H)-one on a 100-mmol (36-g) scale. The benziodoxolone can be used for the gold-catalyzed direct alkynylation of indole, 2-hexylthiophene, ...

2012

Ethynyl Benziodoxolones for the Direct Alkynylation of Heterocycles: Structural Requirement, Improved Procedure for Pyrroles, and Insights into the Mechanism

Rosario Scopelliti, Jérôme Waser, Jonathan Brand

This report describes a full study of the gold-catalyzed direct alkynylation of indoles, pyrroles, and thiophenes using alkynyl hypervalent iodine reagents, especially the study of the structural requirements of alkynyl benziodoxolones for an efficient ace ...

2012

Electrophilic alkynylation: the dark side of acetylene chemistry

Jérôme Waser, Jonathan Brand

In addition to the well-established nucleophilic alkynylation, the use of electrophilic alkynes can expand tremendously the scope of acetylene transfer reactions. The use of metal catalysis has recently led to a rebirth of this research area. Halogenoalkyn ...

Royal Society of Chemistry2012

Development of Catalytic Umpolung : Part 1: Direct Alkynylation of Heterocycles and Electron-Rich Aromatics using Alkynyl-Benziodoxolones - Part 2: Synthesis of New Bifunctional (Thio)urea-Carbene Catalysts

Jonathan Brand

The development of efficient synthetic methodologies is crucial to access complex molecules in an economic, eco-friendly and safe way. The reversal of the intrinsic reactivity of functional groups, called Umpolung, allows alternative synthetic strategies a ...

EPFL2012

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