Search results for "Catalysis"

showing 10 items of 5944 documents

Synthesis of Polycyclic Indolines utilizing a reduction/cyclization cascade reaction

2021

Subsequent reduction and dearomatizing cyclization reactions open up an entry into the synthesis of novel N-fused polycyclic indolines. The dearomatizing cyclization as key step of the sequence proceeds well with Cu(OTf)2 or TfOH as catalyst. At elevated temperature reduction of nitro-substituted precursors with iron under acidic conditions affords a broad variety of polycyclic indolines directly in a two-step cascade reaction in good to excellent yields. Using the developed protocol, the alkaloids Tryptanthrin and Phaitanthrin C have been prepared. peerReviewed

kemiallinen synteesicyclizationkatalyysinitrogen heterocyclescascade reactionshapetus-pelkistysreaktioorgaaniset yhdisteetacid catalysisdearomatization
researchProduct

N-Heterocyclic Carbene Catalyzed Quadruple Domino Reactions through α,β-Unsaturated Acyl Azolium Intermediates : Asymmetric Synthesis of Cyclopenta[c…

2018

An N‐heterocyclic carbene catalyzed domino sequence via α,β‐unsaturated acyl azolium intermediates has been developed. This strategy provides a convenient enantioselective route to functionalized tricyclic coumarin derivatives and cyclopentanes. DFT studies and control experiments were performed to gain better insight into the reaction mechanism. peerReviewed

kemiallinen synteesidomino reactionchromenoneDFT calculationorganocatalysiskumariinitN-heterocyclic carbeneorgaaniset yhdisteet
researchProduct

Synthesis of N‐Monosubstituted Sulfondiimines by Metal‐free Iminations of Sulfiliminium Salts

2023

Sulfondiimines are marginalized entities among nitrogencontaining organosulfur compounds, despite offering promising properties for applications in various fields including medicinal and agrochemical. Herein, we present a metal-free and rapid synthetic procedure for the synthesis of N-monosubstituted sulfondiimines that overcomes current limitations in their synthetic accessibility. Particularly, S,S-dialkyl substrates, which are commonly difficult to convert by existing methods, react well with a combination of iodine, 1,8-diazabicyclo[5.4.0]undec-7-en (DBU), and iminoiodanes (PhINR) in acetonitrile (MeCN) to furnish the corresponding sulfondiimines in yields up to 85% (25 examples). Valua…

kemiallinen synteesiiodineGeneral MedicineGeneral ChemistryrikkiCatalysisjodilääkekemiamedicinal chemistrysulfuriminationtyppiyhdisteetnitrenesulfondiimineorgaaniset yhdisteet
researchProduct

A copper-catalyzed interrupted domino reaction for the synthesis of fused triazolyl benzothiadiazine-1-oxides

2023

Chemistry - a European journal 29(13), e202203729 (2023). doi:10.1002/chem.202203729

kemiallinen synteesikatalyysiddc:540Organic ChemistrykupariGeneral Chemistryheterosykliset yhdisteet540Catalysis
researchProduct

Tetracyclic silaheterocycle formed through a pericyclic reaction cascade including a two-fold intramolecular C–C bond activation

2022

Reductive debromination of the tribromoamidosilane 2 gave the tetracyclic silaheterocycle 3 through a unique reaction cascade involving unprecedented two-fold intramolecular cycloaddition by transient silylenes. Experimental and computational analyses of the reaction mechanism allowed the identification of the key intermediates that lead to the silaheterocycle 3 or, alternatively, to the cyclotrisilene 19. peerReviewed

kemialliset sidoksetMaterials ChemistryMetals and AlloysCeramics and CompositesGeneral Chemistryheterosykliset yhdisteetCatalysisSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsChemical Communications
researchProduct

Selective Synthesis of Z -Silyl Enol Ethers via Ni-Catalyzed Remote Functionalization of Ketones

2021

Journal of the American Chemical Society : JACS 143(22), 8375-8380 (2021). doi:10.1021/jacs.1c01797

ketonesSilylationDimerketonit010402 general chemistry01 natural sciencesBiochemistrytransition metalsCatalysisCatalysischemistry.chemical_compoundkatalyytitColloid and Surface ChemistryPolymer chemistryhydrocarbonsoligomerseetteritkemiallinen synteesiOlefin fiberGeneral ChemistrySilyl enol ether540Enolhiilivedyt3. Good health0104 chemical sciencesoligomeerietherschemistryChain walkingddc:540nikkeliSelectivityJournal of the American Chemical Society
researchProduct

Kernels and Graphs on M25 + H

2023

Codes related to article "Graphs and Kernelized Learning Applied to Interactions of Hydrogen with Doped Gold Nanoparticle Electrocatalysts". There are two main types of codes: codes to transform a catalytic system of protected gold nanoparticle and a single hydrogen atom into a graph-based representation, and codes to run kernel-based machine learning methods to predict interaction energies between the nanoparticle and the hydrogen atom. This is a snapshot of the code dataset that has been taken on 06.06.2023. A more detailed description of the data and the address to the GitLab repository for the latest version of the code can be found from the parent dataset of this data publication.

koneoppiminenkatalyytitmachine learningcatalysiskatalyysinanosciencesnanomateriaalitnanohiukkasetnanoparticlesnanotieteetcatalystsnanomaterials
researchProduct

Kernels and Graphs on M25 + H (parent repository)

2023

The repository contains codes related to article "Graphs and Kernelized Learning Applied to Interactions of Hydrogen with Doped Gold Nanoparticle Electrocatalysts". There are two main types of codes: codes to transform a catalytic system of protected gold nanoparticle and a single hydrogen atom into a graph-based representation, and codes to run kernel-based machine learning methods to predict interaction energies between the nanoparticle and the hydrogen atom. This is the metadata for the parent repository of the codes. Updates and possible corrections are documented in the GitLab project, where the material saved and shared. The GitLab project can be found and downloaded from the followin…

koneoppiminenkatalyytitmachine learningcatalysiskatalyysinanosciencesnanomateriaalitnanohiukkasetnanoparticlesnanotieteetnanomaterialscatalysts
researchProduct

Direct detection of 17O NMR in [Gd(DOTA)]- by NMR Spectroscopy

2015

The 17O NMR spectrum of the non-coordinated carboxyl oxygen in the GdIII-DOTA (DOTA = tetraazacyclododecanetetraacetic acid) complex has been observed experimentally. Its line width is essentially unaffected by paramagnetic relaxation due to gadolinium, and is only affected by the quadrupole pathway. The results are supported by the relevant parameters (hyperfine and quadrupole coupling constants) calculated by relativistic DFT methods. This finding opens up new avenues for investigating the structure and reactivity of paramagnetic GdIII complexes used as contrast agents in magnetic resonance imaging.

lanthanide complexesLanthanideGadoliniumchemistry.chemical_elementImaging agentsCatalysisNMR spectroscopy; Density functional calculations; lanthanide complexes; gadolinium; O-17 nmrParamagnetismchemistry.chemical_compoundNMR spectroscopyNuclear magnetic resonanceLanthanidesDOTAHyperfine structureChemistryOrganic ChemistryRelaxation (NMR)General ChemistryNuclear magnetic resonance spectroscopyDensity functional calculationsSettore CHIM/03 - Chimica Generale E InorganicaQuadrupole17O NMR Lanthanides DFTCondensed Matter::Strongly Correlated ElectronsgadoliniumO-17 nmr
researchProduct

Layered Double Hydroxides: A Toolbox for Chemistry and Biology

2019

Layered double hydroxides (LDHs) are an emergent class of biocompatible inorganic lamellar nanomaterials that have attracted significant research interest owing to their high surface-to-volume ratio, the capability to accumulate specific molecules, and the timely release to targets. Their unique properties have been employed for applications in organic catalysis, photocatalysis, sensors, drug delivery, and cell biology. Given the widespread contemporary interest in these topics, time-to-time it urges to review the recent progresses. This review aims to summarize the most recent cutting-edge reports appearing in the last years. It firstly focuses on the application of LDHs as catalysts in re…

layered double hydroxideGeneral Chemical EngineeringNanotechnology02 engineering and technologycatalysiengineering.material010402 general chemistry01 natural sciencesosteogenesisInorganic Chemistryphotocatalysihydrotalcitelcsh:QD901-999General Materials ScienceSettore FIS/03catalysisChemistryLayered double hydroxidesDNARNA.021001 nanoscience & nanotechnologyCondensed Matter PhysicsBiocompatible materialosteogenesilayered double hydroxides0104 chemical sciencesNanotoxicologycellular biologyDrug deliverydrug deliveryengineeringRNAlcsh:Crystallography0210 nano-technologyphotocatalysisCrystals
researchProduct