Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Copper-Catalyzed Homo-Dimerization of Nitronates and Enolates under Oxygen Atmosphere.

ABSTRACT: A method for copper-catalyzed oxidative dimerization of nitronates and enolates using oxygen as terminal oxidant has been developed. Cyclization through oxidative intramolecular coupling is also feasible for both nitronates and enolates. The mild reaction conditions lead to good functional group tolerance.

SUBMITTER: Do HQ

PROVIDER: S-EPMC3568985 | biostudies-literature | 2012 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Copper-Catalyzed Homo-Dimerization of Nitronates and Enolates under Oxygen Atmosphere.

Do Hien-Quang HQ Tran-Vu Hung H Daugulis Olafs O

Organometallics 20120621 22

A method for copper-catalyzed oxidative dimerization of nitronates and enolates using oxygen as terminal oxidant has been developed. Cyclization through oxidative intramolecular coupling is also feasible for both nitronates and enolates. The mild reaction conditions lead to good functional group tolerance. ...[more]

PMID: 23413317

Similar Datasets

Copper-Catalyzed Dimerization/Cyclization of Itaconates.

Project description:A copper-catalyzed domino reaction between itaconate esters and diethyl zinc (or silane) is developed, affording itaconate dimerization products, multi-ester-substituted cyclopentanones, in moderate to high yields.

| S-EPMC6332366 | biostudies-literature

A general method for copper-catalyzed arene cross-dimerization.

Project description:A general method for a highly regioselective copper-catalyzed cross-coupling of two aromatic compounds using iodine as an oxidant has been developed. The reactions involve an initial iodination of one arene followed by arylation of the most acidic C-H bond of the other coupling component. Cross-coupling of electron-rich arenes, electron-poor arenes, and five- and six-membered heterocycles is possible in many combinations. Typically, a 1/1.5 to 1/3 ratio of coupling components is used, in contrast to existing methodology that often employs a large excess of one of the arenes. Common functionalities such as ester, ketone, aldehyde, ether, nitrile, nitro, and amine are well-tolerated.

| S-EPMC3168561 | biostudies-literature

Copper-catalyzed oxidative homo- and cross-coupling of Grignard reagents using diaziridinone.

Project description:Transition-metal-catalyzed cross-coupling reactions are among the most powerful synthetic transformations. This paper describes an efficient copper-catalyzed homo- and cross-coupling of Grignard reagents with di-tert-butyldiaziridinone as oxidant under mild conditions, giving the coupling products in good to excellent yields. The reaction process has a broad substrate scope and is also effective for the C(sp)-C(sp(3)) coupling.

| S-EPMC4260645 | biostudies-literature

Mononuclear copper complex-catalyzed four-electron reduction of oxygen.

Project description:A mononuclear Cu(II) complex acts as an efficient catalyst for four-electron reduction of O(2) to H(2)O. Its reduction by a ferrocene derivative (Fc*) and reaction with O(2) leads to the formation of a peroxodicopper(II) complex; this is subsequently reduced by Fc* in the presence of protons to regenerate the Cu(II) complex.

| S-EPMC2886287 | biostudies-literature

Solvent-free copper-catalyzed azide-alkyne cycloaddition under mechanochemical activation.

Project description:The ball-mill-based mechanochemical activation of metallic copper powder facilitates solvent-free alkyne-azide click reactions (CuAAC). All parameters that affect reaction rate (i.e., milling time, revolutions/min, size and milling ball number) have been optimized. This new, efficient, facile and eco-friendly procedure has been tested on a number of different substrates and in all cases afforded the corresponding 1,4-disubstituted 1,2,3-triazole derivatives in high yields and purities. The final compounds were isolated in almost quantitative overall yields after simple filtration, making this procedure facile and rapid. The optimized CuAAC protocol was efficiently applied even with bulky functionalized ?-cyclodextrins (?-CD) and scaled-up to 10 g of isolated product.

| S-EPMC6272186 | biostudies-other

Diastereo- and enantioselective iridium-catalyzed allylation of cyclic ketone enolates: synergetic effect of ligands and barium enolates.

Project description:We report asymmetric allylic alkylation of barium enolates of cyclic ketones catalyzed by a metallacyclic iridium complex containing a phosphoramidite ligand derived from (R)-1-(2-naphthyl)ethylamine. The reaction products contain adjacent quaternary and tertiary stereocenters. This process demonstrates that unstabilized cyclic ketone enolates can undergo diastereo- and enantioselective Ir-catalyzed allylic substitution reactions with the proper choice of enolate countercation. The products of these reactions can be conveniently transformed to various useful polycarbocyclic structures.

| S-EPMC4235373 | biostudies-literature

Inner-sphere mechanism for molecular oxygen reduction catalyzed by copper amine oxidases.

Project description:Copper and topaquinone (TPQ) containing amine oxidases utilize O2 for the metabolism of biogenic amines while concomitantly generating H2O2 for use by the cell. The mechanism of O2 reduction has been the subject of long-standing debate due to the obscuring influence of a proton-coupled electron transfer between the tyrosine-derived TPQ and copper, a rapidly established equilibrium precluding assignment of the enzyme in its reactive form. Here, we show that substrate-reduced pea seedling amine oxidase (PSAO) exists predominantly in the Cu(I), TPQ semiquinone state. A new mechanistic proposal for O2 reduction is advanced on the basis of thermodynamic considerations together with kinetic studies (at varying pH, temperature, and viscosity), the identification of steady-state intermediates, and the analysis of competitive oxygen kinetic isotope effects, (18)O KIEs, [kcat/KM((16,16)O2)]/[kcat/KM((16,18)O2)]. The (18)O KIE = 1.0136 +/- 0.0013 at pH 7.2 is independent of temperature from 5 degrees C to 47 degrees C and insignificantly changed to 1.0122 +/- 0.0020 upon raising the pH to 9, thus indicating the absence of kinetic complexity. Using density functional methods, the effect is found to be precisely in the range expected for reversible O2 binding to Cu(I) to afford a superoxide, [Cu(II)(eta(1)-O2)(-I)](+), intermediate. Electron transfer from the TPQ semiquinone follows in the first irreversible step to form a peroxide, Cu(II)(eta(1)-O2)(-II), intermediate driving the reduction of O2. The similar (18)O KIEs reported for copper amine oxidases from other sources raise the possibility that all enzymes react by related inner-sphere mechanisms although additional experiments are needed to test this proposal.

| S-EPMC2574554 | biostudies-literature

Copper-catalyzed C-H acyloxylation of 2-phenylpyridine using oxygen as the oxidant.

Project description:An efficient copper-catalyzed direct o-acyloxylation of 2-phenylpyridine with carboxylic acids using oxygen as the oxidant has been developed. Various acids including aromatic acids, cinnamic acids and aliphatic acids are effective acyloxylation reagents and provide the desired products in moderate to excellent yields. The reaction proceeds well under an oxygen atmosphere, making this method potentially practical.

| S-EPMC9080246 | biostudies-literature

C-Boron Enolates Enable Palladium Catalyzed Carboboration of Internal 1,3-Enynes.

Project description:A new family of carbon-bound boron enolates, generated by a kinetically controlled halogen exchange between chlorocatecholborane and silylketene acetals, is described. These C-boron enolates are demonstrated to activate 1,3-enyne substrates in the presence of a Pd0 /Senphos ligand complex, resulting in the first examples of a carboboration reaction of an alkyne with enolate-equivalent nucleophiles. Highly substituted dienyl boron building blocks are produced in excellent site-, regio-, and diastereoselectivity by the described catalytic cis-carboboration reaction.

| S-EPMC8440383 | biostudies-literature

Pd-catalyzed α-arylation of trimethylsilyl enolates of α,α-difluoroacetamides.

Project description:We report the arylation and heteroarylation of α,α-difluoro-α-(trimethylsilyl)acetamides with aryl and heteroaryl bromides catalyzed by an air- and moisture-stable palladacyclic complex containing P(t-Bu)2Cy as ligand. A broad range of electronically varied aryl and heteroaryl bromides underwent this transformation to afford α-aryl-α,α-difluoroacetamides in high yields. Due to the electrophilicity of the fluorinated amide, this palladium-catalyzed cross-coupling reaction provides a versatile platform to generate a range of α,α-difluoro carbonyl compounds, such as α-aryl-α,α-difluoroketones, -acetaldehydes, -acetates, and acetic acids, and difluoroalkyl derivatives, such as 2-aryl-2,2-difluoroethanols and -ethylamines, under mild conditions.

| S-EPMC4210146 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data