Publications associées à Diastéréoisomérie

Dielectric Tetramer Nanoresonators Supporting Strong Superchiral Fields for Vibrational Circular Dichroism Spectroscopy

Hatice Altug, Felix Ulrich Richter, Yasaman Jahani, Rui Lu, Bang Hyun Lee, Ming-Lun Tseng, Longfang Ye

Chirality (C) is a fundamental property of objects, in terms of symmetry. It is extremely important to sense and distinguish chiral molecules in the fields of biochemistry, science, and medicine. Vibrational circular dichroism (VCD) spectroscopy, obtained ...

Amer Chemical Soc2023

Enantioselective Total Synthesis of (+)-Nordasycarpidone, (+)-Dasycarpidone, and (+)-Uleine

Qian Wang, Jieping Zhu, Cédric Fung, Bastien Delayre

The structure of uleine type alkaloids is characterized by the presence of a bridged tetracyclic hexahydro-1H-1,5-methanoazocino[4,3-b]indole ring system 1. Various strategies have been developed to access this polycyclic structural motif. We report herein ...

2021

Indole Alkaloids, Macrocycles and Heterocycles : Interplay between Methodological Development and Total Synthesis

Cyril Piemontesi

An enantioselective total synthesis of (-)-terengganensine A, a heptacyclic monoterpene indole alkaloid, was performed. A short sequence allowed to obtain the enantio-enriched target in good overall yield. The synthesis featured a key asymmetric transfer h ...

EPFL2018

Dearomatization of electron poor six-membered N-heterocycles through [3+2] annulation with aminocyclopropanes

Jérôme Waser, Johannes Preindl, Shyamal Chakrabarty

Many abundant and highly bioactive natural alkaloids contain an indolizidine skeleton. A simple, high yielding method to synthesize this scaffold from N-heterocycles was developed. A wide range of pyridines, quinolines and isoquinolines reacted with donor- ...

2017

Remotely Controlled Isomer Selective Molecular Switching

Klaus Kern, Uta Schlickum, Hagen Klauk, Peter Wahl, Ivan Pentegov, Verena Katharina Schendel

Non local addressing-the "remote control"- of molecular switches promises more efficient processing for information technology, where fast speed of switching is essential. The surface state of the (111) facets of noble metals, a confined two-dimensional el ...

Amer Chemical Soc2016

Chiral N-Heterocyclic Carbene Ligand Enabled Nickel(0)-Catalyzed Enantioselective Three-Component Couplings as Direct Access to Silylated Indanols

Nicolai Cramer, Joachim Sven Ernst Ahlin

An enantioselective nickel(0)-catalyzed reductive three-component coupling between aromatic aldehydes, norbornenes, and silanes affords directly silyl-protected indanol derivatives. A new bulky chiral C-2-symmetric NHC (NHC = N-heterocyclic carbene) ligand ...

American Chemical Society2016

An Enantioselective Total Synthesis of (−)-Isoschizogamine

Qian Wang, Jieping Zhu, Xu Bao, Zhengren Xu

A concise enantioselective total synthesis of (¢)- isoschizogamine, a complex bridged polycyclic monoterpene indole alkaloid, was accomplished. N-Alkylation of an enantio- enriched imine with an alkyl iodide afforded an iminium salt, which, upon heating by ...

Wiley-Blackwell2015

Phosphoric Acid Catalyzed Diastereo- and Enantioselective Synthesis of Substituted 1,3-Diaminotetralins

Jieping Zhu

The reaction of anilines and phenylacetaldehydes in the presence of chiral phosphoric acid afforded optically active 1,2-trans, 2,3-cis 1,3-diaminotetralins in high yields with excellent diastereo- and enantioselectivities. The trans/cis product was readil ...

Amer Chemical Soc2014

Ruthenium(II) arene PTA (RAPTA) complexes: impact of enantiomerically pure arene ligands

Paul Joseph Dyson, Catherine Marie Amélie Clavel, Kelly Joan Kilpin, Shona Cammack

Organometallic ruthenium(II) arene complexes containing the PTA ligand ([Ru(eta(6)-arene)Cl-2(PTA)], PTA = 1,3,5-triaza-7-phosphatricyclo-[3.3.1.1] decane, termed RAPTA) show pharmacologically relevant antitumour properties in vitro. Two new enantiomeric p ...

Royal Society of Chemistry2013

The tautomeric structures of 3(5),3 '(5 ')-azopyrazole [(E)-1,2-di(1H-pyrazol-3(5)-yl)diazene)]: The combined use of NMR and electronic spectroscopies with DFT calculations

Pablo Lopez Tarifa

An azo derivative of 1H-pyrazole has been chosen to study the information obtained from different techniques for determining the structure of a non-crystalline compound in the solid-state and in solution. Syn-anti isomerism of the azo group, prototropic ta ...

2012

Catalytic Enantiospecific [3+2] Annulation of Aminocyclopropanes with Ketones

Jérôme Waser, Fides Benfatti, Florian Patrick Marie Daniel De la Barre De Nanteuil

The first enantiospecific [3+2] annulation of D-A amino-cyclopropanes with ketones is reported herein (see scheme; Phth = phthaloyl). The reaction is catalyzed by 5 mol % of tin(IV) chloride at -78 °C and gives aminotetra-hydrofurans bearing a C5-quaternar ...

2012

Isomerization Mechanisms of Stereolabile tris- and bis-Bidentate Octahedral Cobalt(II) Complexes: X-ray Structure and Variable Temperature and Pressure NMR Kinetic Investigation

André Merbach, Rosario Scopelliti, Lothar Helm, Fabrice Riblet

The isomerization dynamics of five labile octahedral Co(II) compounds have been investigated by variable temperature and pressure 1H and 19F NMR spectroscopy in dichloromethane solution. The X-ray crystal structure of the two tris-chelates, [Co(HFA)2bpic] ...

American Chemical Society2010

Role of Adsorbed H, C, O, and CO on the Atomic Structure of Free and MgO(100)-Supported Ir-4 Clusters: An ab Initio Study

Alfonso Baldereschi, Zeljko Sljivancanin, Vladan Stevanovic

We applied density functional theory based on ultrasoft pseudopotentials to study the structural properties of Ir-4 clusters both in the gas phase and adsorbed on a MgO(100) surface. To resolve the discrepancy between experimental data which suggest a tetr ...

2010

Reactivity Of Arylnitrile Oxides And C-Aroyl-N-Phenylnitrones With 3-Methylenedihydro-(3H)-Furan-2-One And Itaconic Anhydride

Christophe Roussel

1,3-dipolar cycloaddition is a powerful route for the synthesis of five-membered heterocycles. The [3+2] cycloadditions of some alpha-methylene-gamma-buryrolactones, namely 3-methylenedihydro-(3H)-furan-2-one (1) and itaconic anhydride (2) were Studied. Th ...

2009

Recent Synthetic Approaches Toward Non-anomeric Spiroketals in Natural Products

Pierre Vogel, Sandrine Gerber, Sylvain Favre

Many natural products of biological interest contain [6,5]- and [6,6]-spiroketal moieties that can adopt various configurations, benefiting or not from anomeric conformation stabilizing effects. The spiroketal fragments are often important for the biologic ...

2008

Embedding an Allylmetal Dimer in a Chiral Cavity: The Unprecedented Stereoselectivity of a Twofold Wittig [1,2]-Rearrangement

Frédéric Bailly

After alpha,alpha'-dimetalation, both 2,2'-diallyloxy-1,1'-binaphthyl and 2,2'-di-2-methylallyloxy-1,1'-binaphthyl undergo the Wittig rearrangement with perfect diastereoselectivity. When racemic 1,1'-binaphthyl-2,2'-diol ("BINOL") is used as the starting ...

2006