Browse
Submit Data
Databases
API
Help

Dataset Information

20 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Pyrrolidine-mediated direct preparation of (e)-monoarylidene derivatives of homo- and heterocyclic ketones with various aldehydes.

ABSTRACT: An efficient method for the facile synthesis of (E)-monoarylidene derivatives of homo- and heterocyclic ketones with various aldehydes in the presence of a pyrrolidine organocatalyst has been achieved. A range of ?,?-unsaturated ketones were obtained in moderate to high yields (up to 99%). Unlike the Claisen-Schmidt condensation process, the formation of undesired bisarylidene byproducts is not observed. The possible reaction mechanism suggests that the reaction proceeds via a Mannich-elimination sequence.

SUBMITTER: Gu X

PROVIDER: S-EPMC6271378 | biostudies-literature | 2014 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Pyrrolidine-mediated direct preparation of (e)-monoarylidene derivatives of homo- and heterocyclic ketones with various aldehydes.

Gu Xin X Wang Xiaoyan X Wang Fengtian F Sun Hongbao H Liu Jie J Xie Yongmei Y Xiang Mingli M

Molecules (Basel, Switzerland) 20140212 2

An efficient method for the facile synthesis of (E)-monoarylidene derivatives of homo- and heterocyclic ketones with various aldehydes in the presence of a pyrrolidine organocatalyst has been achieved. A range of α,β-unsaturated ketones were obtained in moderate to high yields (up to 99%). Unlike the Claisen-Schmidt condensation process, the formation of undesired bisarylidene byproducts is not observed. The possible reaction mechanism suggests that the reaction proceeds via a Mannich-eliminatio ...[more]

PMID: 24526254

Similar Datasets

Palladium-catalyzed, pyrrolidine-mediated arylmethylation of ketones and aldehydes with coumarinyl(methyl) acetates.

Project description:We report the palladium-catalyzed, pyrrolidine-mediated α-benzylation of enamines generated from aldehydes and ketones. The method allows for direct coupling of medicinally relevant coumarin moieties with aldehydes and ketones in good yield under mild conditions. The reaction is believed to proceed via a Pd-π-benzyl complex generated from (coumarinyl)methyl acetates.

| S-EPMC3443958 | biostudies-literature

Photoredox activation for the direct β-arylation of ketones and aldehydes.

Project description:The direct β-activation of saturated aldehydes and ketones has long been an elusive transformation. We found that photoredox catalysis in combination with organocatalysis can lead to the transient generation of 5π-electron β-enaminyl radicals from ketones and aldehydes that rapidly couple with cyano-substituted aryl rings at the carbonyl β-position. This mode of activation is suitable for a broad range of carbonyl β-functionalization reactions and is amenable to enantioselective catalysis.

| S-EPMC3723331 | biostudies-literature

Reductions of aldehydes and ketones with a readily available N-heterocyclic carbene borane and acetic acid.

Project description:Acetic acid promotes the reduction of aldehydes and ketones by the readily available N-heterocyclic carbene borane, 1,3-dimethylimidazol-2-ylidene borane. Aldehydes are reduced over 1-24 h at room temperature with 1 equiv of acetic acid and 0.5 equiv of the NHC-borane. Ketone reductions are slower but can be accelerated by using 5 equiv of acetic acid. Aldehydes can be selectively reduced in the presence of ketones. On a small scale, products are isolated by evaporation of the reaction mixture and direct chromatography.

| S-EPMC3629027 | biostudies-literature

C(sp<sup>3</sup>)-C(sp<sup>3</sup>) bond formation via nickel-catalyzed deoxygenative homo-coupling of aldehydes/ketones mediated by hydrazine.

Project description:Aldehydes and ketones are widely found in biomass resources and play important roles in organic synthesis. However, the direct deoxygenative coupling of aldehydes or ketones to construct C(sp3)-C(sp3) bond remains a scientific challenge. Here we report a nickel-catalyzed reductive homo-coupling of moisture- and air-stable hydrazones generated in-situ from naturally abundant aldehydes and ketones to construct challenging C(sp3)-C(sp3) bond. This transformation has great functional group compatibility and can suit a broad substrate scope with innocuous H2O, N2 and H2 as the by-products. Furthermore, the application in several biological molecules and the transformation of PEEK model demonstrate the generality, practicability, and applicability of this novel methodology.

| S-EPMC8211713 | biostudies-literature

Base-Mediated Meerwein-Ponndorf-Verley Reduction of Aromatic and Heterocyclic Ketones.

Project description:An experimental protocol to achieve the Meerwein-Ponndorf-Verley (MPV) reduction of ketones under mildly basic conditions is reported. The transformation is tolerant of a range of ketone substrates, including O- and S-containing heterocycles, is scalable, and shows potential to be used as a platform to access enantioenriched products. These studies provide a general method for achieving the reduction of ketones under mildly basic conditions and offer an alternative protocol to more well-known Al-based MPV reduction conditions.

| S-EPMC7193670 | biostudies-literature

Direct Aerobic ?, ?-Dehydrogenation of Aldehydes and Ketones with a Pd(TFA)(2)/4,5-Diazafluorenone Catalyst().

Project description:The direct ?, ?-dehydrogenation of aldehydes and ketones represents an efficient alternative to stepwise methods to prepare enal and enone products. Here, we describe a new Pd(TFA)(2)/4,5-diazafluorenone dehydrogenation catalyst that overcomes key limitations of previous catalyst systems. The scope includes successful reactivity with pharmaceutically important cyclopentanone and flavanone substrates, as well as acyclic ketones. Preliminary mechanistic studies compare the reactivity of this catalyst to previously reported dehydrogenation catalysts and reveal that cleavage of the ?-C-H bond of the ketone is the turnover-limiting step of the catalytic mechanism.

| S-EPMC3370690 | biostudies-literature

Direct Conversion of Aldehydes and Ketones to Allylic Halides by a NbX(5-)[3,3] Rearrangement.

Project description:Sequential addition of vinylmagnesium bromide and NbCl(5), or NbBr(5), to a series of aldehydes and ketones directly provides homologated, allylic halides. Transposition of the intermediate vinyl alkoxide is envisaged through a metalla-halo-[3,3] rearrangement with concomitant delivery of the halogen to the terminal carbon. The [3,3] rearrangement is equally effective for the conversion of a propargyllic alcohol to the corresponding allenyl bromide.

| S-EPMC2709853 | biostudies-literature

Indium-mediated allylation of aldehydes, ketones and sulfonimines with 2-(alkoxy)allyl bromides.

Project description:2-(Alkoxy)propenyl bromides are readily prepared from 1,3-dibromo-2-propanol in a two-step sequence involving hydroxyl protection and sodium hydride-induced dehydrobromination. Indium-mediated allylation of aldehydes, ketones, and sulfonimines with 2-(alkoxy)propenyl bromides furnishes the corresponding homoallylic alcohols and sulfonamines in good yields. The products can be easily transformed into ?-hydroxy ketones and esters, as well as substituted dihydropyrans and protected ?-amino acids. Chiral 2-(alkoxy)propenyl halides, derived from (-)-menthol and D-glucal, furnish diastereomerically enriched products.

| S-EPMC2976063 | biostudies-literature

Cyano-borrowing reaction: nickel-catalyzed direct conversion of cyanohydrins and aldehydes/ketones to β-cyano ketone.

Project description:A direct nickel-catalyzed, high atom- and step-economical reaction of cyanohydrins with aldehydes or ketones via an unprecedented "cyano-borrowing reaction" has been developed. Cleavage of the C-CN bond of cyanohydrins followed by aldol condensation and conjugate addition of cyanide to α,β-unsaturated ketones proceeded to deliver a range of racemic β-cyano ketones with good to high yields. The practical procedure with the use of a commercial and less-toxic CN source bodes well for wide application of this protocol.

| S-EPMC6568282 | biostudies-literature

A convenient and eco-friendly cerium(III) chloride-catalysed synthesis of methoxime derivatives of aromatic aldehydes and ketones.

Project description:The use of CeCl3·7H2O as an efficient and eco-friendly promoter for the convenient synthesis of methoximes derived from aromatic aldehydes and ketones, is reported. The transformations entail the use of equimolar amounts of MeONH2·HCl and NaOAc in EtOH at 50°C, and no special precautions are needed with regard to the presence of oxygen. The scope and limitations of the transformation were studied and a reaction mechanism was proposed.

| S-EPMC5990813 | 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