Publications related to Leaving group

(4+3) Annulation of Donor-Acceptor Cyclopropanes and Azadienes: Highly Stereoselective Synthesis of Azepanones

Azepanes are important seven-membered heterocycles, which are present in numerous natural and synthetic compounds. However, the development of convergent synthetic methods to access them remains challenging. Herein, we report the Lewis acid catalyzed (4+3) ...

Wiley-VCH Verlag GmbH2022

Access to Vinyl Ethers and Ketones with Hypervalent Iodine Reagents as Oxy-Allyl Cation Synthetic Equivalents

Jérôme Waser, Nina Declas

We report an Umpolung strategy of enol ethers to generate oxy-allyl cation equivalents based on the use of hypervalent iodine reagents. Under mild basic conditions, the addition of nucleophiles to aryloxy-substituted vinylbenziodoxolone (VBX) reagents, eas ...

Wiley-VCH Verlag GmbH2020

Towards the Sarpagine-Ajmaline-Macroline Family of Indole Alkaloids: Enantioselective Synthesis of an N-Demethyl Alstolactone Diastereomer

Qian Wang, Jieping Zhu, Dylan Jean Robert Dagoneau

the strategy involving the use of functionalized tetrahydro-6H-cycloocta[b]indol-6-one is reported as a key intermediate for synthesis of members of the sarpagine-ajmaline-macroline family of monoterpene indole alkaloids. The desired tricycle was synthesiz ...

WILEY-V C H VERLAG GMBH2020

Neutral chiral cyclopentadienyl Ru(II)Cl catalysts enable enantioselective [2+2]-cycloadditions

Nicolai Cramer, David Kossler

Cyclopentadienyl ruthenium(II) complexes with a large number of available coordination sites are frequently used catalysts for a broad range of transformations. To be able to render these transformations enantioselective, we have designed a chiral neutral ...

2017

Polyimidazolium Salts: Robust Catalysts for the Cycloaddition of Carbon Dioxide into Carbonates in Solvent-Free Conditions

Paul Joseph Dyson, Zhaofu Fei, Felix Daniel Bobbink, Wei Zhong

There is a growing interest in sustainable heterogeneous catalysts based on organic polymers. Here, we describe a series of polyimidazolium salt catalysts, prepared from the direct reaction of arene- bridged bis- and tris-alkyl halides with trimethylsilyli ...

Wiley-V C H Verlag Gmbh2017

"Palladium-Catalyzed Diamination of Alkynes in Synthesis of Tetracycles" and "Copper-Catalyzed Cyanoalkylation of Unactivated Alkenes"

Minh Tu Ha

The thesis deals with the development of transition metal-catalyzed difunctionalization of alkenes and alkynes, which can be categorized into two major topics: (1) palladium-catalyzed diamination of alkynes for the synthesis of tetracycles; (2) copper-cata ...

EPFL2017

Equilibria and Speciation of Chloramines, Bromamines, and Bromochloramines in Water

Jeremy Samuel Arey, Daniela Trogolo

The stabilities and speciation of the halamines in water are difficult to characterize experimentally. We provide theoretical estimates of aqueous standard free energies of formation for inorganic chloramines, bromamines, and bromochloramines, based on hig ...

Amer Chemical Soc2017

Synthesis of Oxazolidin-2-ones by Oxidative Coupling of Isonitriles, Phenyl Vinyl Selenone, and Water

Qian Wang, Jieping Zhu, Thomas Bertrand Pascal Marie Buyck, Delphine Pasche

Reaction of alkyl isocyanides, phenyl vinyl selenone, and water in the presence of a catalytic amount of Cs2CO3 afforded oxazolidin-2-ones in good yields. This unprecedented heteroannulation process created four chemical bonds in a single operation with th ...

Wiley-Blackwell2016

Benziodoxol(on)e Reagents as Tools in Organic Synthesis: The Background behind the Discovery at the Laboratory of Catalysis and Organic Synthesis

Jérôme Waser

In this review, a personal account of our work in the field of hypervalent iodine reagents is presented. Pioneering experiments, which led to the discovery of the exceptional reactivity of EthynynnnlBenziodoXol( on)e (EBX) reagents as electrophilic alkyne ...

2016

Switchable [3+2] and [4+2] Heteroannulation of Primary Propargylamines with Isonitriles to Imidazoles and 1,6-Dihydropyrimidines: Catalyst Loading Enabled Reaction Divergence

Qian Wang, Jieping Zhu, Shuo Tong

Isonitrile 1 due to its carbene-like reactivity serves generally as a one-carbon synthon in a diverse set of organic transformations. We report in this article that the isocyano group can also act as a polarized triple bond to undergo, as a two-atom syntho ...

Wiley-Blackwell2016

Are reactions between allylpotassiums and halotrimethylsilanes diffusion-controlled?

Eric Masson

The order of reactivity (X = F < Cl < Br < I) determined for the reaction of the model nucleophile pinenylpotassium with halotrimethylsilanes XSi(CH3)(3) in hexane and with halotriisopropylsilanes XSi(iC(3)H(7))(3) in tetrahydrofuran supports a single-step ...

Arkat Usa Inc2015

Reconstitution of [Fe]-hydrogenase using model complexes

Xile Hu, Matthew Wodrich, Tao Xu, Dafa Chen

[Fe]-Hydrogenase catalyses the reversible hydrogenation of a methenyltetrahydromethanopterin substrate, which is an intermediate step during the methanogenesis from CO2 and H-2. The active site contains an iron-guanylylpyridinol cofactor, in which Fe2+ is ...

Nature Publishing Group2015

Isocyanoacetates as Synthetic Platform Towards Natural Products and Biologically Relevant Scaffolds

Thomas Bertrand Pascal Marie Buyck

My PhD work started with the development of a racemic access to trigonoliimine B, an hexacyclic alkaloid isolated in 2010. After having explored different strategies, we reported a 7-step synthesis of this natural product. This synthesis features a challen ...

EPFL2014

DNA Reactivity Profile of trans-Platinum Planar Amine Derivatives

Alexey Nazarov

New trans-platinum planar amines (TPAs) represent a family of platinum-based drugs with cytotoxicity equivalent to that of cisplatin, but with negligible cross-resistance. According to the substitution pattern around the metal center, distinct DNA adducts ...

2011

Synthesis of D- and L-erythro 1,5-dithiopent-1-enopyranoside sulfonium salts and their evaluation as glycosidase inhibitors

Pierre Vogel, Claudia Bello

A series of sulfonium salts derived from 1,5-dithiopent-1-enopyranosides was prepared in a three-step sequence from protected D- and L-erythrofuranoses. The key step is the nucleophilic displacement of a leaving group by a sulfur atom of carbohydrate-deriv ...

2009

Cyclization of Cyclopropyl Carbonyls and the Homo-Nazarov Reaction

Jérôme Waser, Filippo De Simone

Ring strain confers to the cyclopropane ring an exceptional reactivity. Nevertheless, activation of the cyclopropane ring is usually needed to allow ring-opening reactions under mild conditions. The introduction of one or several carbonyl functionalities o ...

2009

Cyclization and Cycloaddition Reactions of Cyclopropyl Carbonyls and Imines

Jérôme Waser, Filippo De Simone

Activated cyclopropanes, such as vinyl and carbonyl cyclopropanes, are useful building blocks in organic chemistry due to their exceptional reactivity. This review focuses on the use of cyclopropyl carbonyls and imines in cyclization and cycloaddition reac ...

Georg Thieme Verlag2009

Phosphodiester Cleavage in Ribonuclease H Occurs via an Associative Two-Metal-Aided Catalytic Mechanism

Matteo Dal Peraro

Ribonuclease H (RNase H) belongs to the nucleotidyl-transferase (NT) superfamily and hydrolyzes the phosphodiester linkages that form the backbone of the RNA strand in RNA x DNA hybrids. This enzyme is implicated in replication initiation and DNA topology ...

2008

Relative carbanion basicities as driving force for an intramolecular silyl migration of lithiated biphenyls

Rosario Scopelliti

A solvent-dependent silyl migration of lithiated biphenyls is described, involving the intermediate formation of a pentacoordinated silicate complex. Differences in the relative basicities of the aryllithium intermediates are the possible driving force for ...

Elsevier2007

Wittig rearrangement of lithiated allyl aryl ethers: a mechanistic study

A -75 DegC, alpha-lithiated allyl Ph ether undergoes mainly the Wittig rearrangement to afford, after acidic hydrolysis, 1-phenyl-2-propen-1-ol as the main product. A second metalation taking place at one of the ortho positions is the sole competing side r ...

2006