Browse
Submit Data
Databases
API
Help

Dataset Information

30 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Asymmetric epoxidation of fluoroolefins by chiral dioxirane. Fluorine effect on enantioselectivity.

ABSTRACT: The asymmetric epoxidation of various fluoroolefins has been studied using chiral ketone catalyst, and up to 93% ee was achieved with fructose-derived ketone 1.

SUBMITTER: Wong OA

PROVIDER: S-EPMC2784290 | biostudies-literature | 2009 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Asymmetric epoxidation of fluoroolefins by chiral dioxirane. Fluorine effect on enantioselectivity.

Wong O Andrea OA Shi Yian Y

The Journal of organic chemistry 20091101 21

The asymmetric epoxidation of various fluoroolefins has been studied using chiral ketone catalyst, and up to 93% ee was achieved with fructose-derived ketone 1. ...[more]

PMID: 19795858

Similar Datasets

Asymmetric epoxidation of 1,1-disubstituted terminal olefins by chiral dioxirane via a planar-like transition state.

Project description:Various 1,1-disubstituted terminal olefins have been investigated for asymmetric epoxidation using chiral ketone catalysts. Up to 88% ee has been achieved with a lactam ketone, and a planar transition state is likely to be a major reaction pathway.

| S-EPMC2736380 | biostudies-literature

Enantioselective epoxidation of nonconjugated cis-olefins by chiral dioxirane.

Project description:A variety of nonconjugated cis-olefins has been enantioselectively epoxidized with chiral ketones 2, and up to 92% ee has been obtained. The two prochiral faces of an olefin are likely stereodifferentiated by the relative hydrophobicity of the olefin substituents and/or allylic oxygen functionality.

| S-EPMC2783705 | biostudies-literature

Effect of sulfide structure on enantioselectivity in catalytic asymmetric epoxidation of aldehydes: mechanistic insights and implications.

Project description:Bridged bicyclic sulfide 1 was originally found to provide high levels of asymmetric induction in sulfur ylide-mediated epoxidations. This sulfide possesses chirality in the [2.2.1] thioether moiety and the [2.2.1] camphor-derived carbocyclic moiety. To determine whether the optimal sulfide had been used, a diastereomer of sulfide 1 in which the stereochemistry of the [2.2.1] carbocycle was reversed (sulfide 5) was prepared and studied as an epoxidation catalyst. This diastereomer gave considerably lower levels of asymmetric induction than the original sulfide 1. From computational and x-ray studies it was found that sulfide 5 gave rise to a more hindered ylide, which reacted more reversibly with aldehydes leading to lower enantioselectivity. Conditions that reduced reversibility were also tested and high enantioselectivities were returned for sulfide 5 (similar to sulfide 1). The implications for the synthesis of chiral sulfides for asymmetric epoxidations are discussed.

| S-EPMC397406 | biostudies-literature

Asymmetric Cyclopropanation and Epoxidation via a Catalytically Formed Chiral Auxiliary.

Project description:For the enantioselective diversification of a single starting material, a different chiral catalyst is usually required for each transformation. Herein, we extend the concept of catalytically formed chiral auxiliary from hydrogenation to the asymmetric cyclopropanation and epoxidation of tetra-substituted olefins, alleviating the need for different chiral catalysts in the alkene functionalization step. The chiral auxiliary is catalytically constructed from propargylic amines in a Pd-catalyzed enantioselective carboetherification step using a commercially available trifluoroacetaldehyde hemiacetal tether. The installed auxiliary is then controlling the stereochemistry of the cyclopropanation and the epoxidation using standard highly reactive reagents to give enantioenriched spirocyclic aminomethylcyclopropanols and α-amino-α-hydroxy ketones.

| S-EPMC9306854 | biostudies-literature

Reagent-controlled enantioselectivity switch for the asymmetric fluorination of ?-ketocarbonyls by chiral primary amine catalysis.

Project description:A reagent-controlled enantioselectivity switch was uncovered in the asymmetric ?-fluorination of ?-ketocarbonyls by a chiral primary amine catalyst. By a simple swap of fluorination reagents, both enantiomers of the quaternary fluorination adducts could be obtained with good yields and high enantioselectivity. Mechanistic studies disclosed dual H-bonding and electrostatic stereocontrolling modes for the catalysis.

| S-EPMC5358536 | biostudies-literature

Holistic prediction of enantioselectivity in asymmetric catalysis.

Project description:When faced with unfamiliar reaction space, synthetic chemists typically apply the reported conditions (reagents, catalyst, solvent and additives) of a successful reaction to a desired, closely related reaction using a new substrate type. Unfortunately, this approach often fails owing to subtle differences in reaction requirements. Consequently, an important goal in synthetic chemistry is the ability to transfer chemical observations quantitatively from one reaction to another. Here we present a holistic, data-driven workflow for deriving statistical models of one set of reactions that can be used to predict out-of-sample reactions. As a validating case study, we combined published enantioselectivity datasets that employ 1,1'-bi-2-naphthol (BINOL)-derived chiral phosphoric acids for a range of nucleophilic addition reactions to imines and developed statistical models. These models reveal the general interactions that impart asymmetric induction and allow the quantitative transfer of this information to new reaction components. This technique creates opportunities for translating comprehensive reaction analysis to diverse chemical space, streamlining both catalyst and reaction development.

| S-EPMC6641578 | biostudies-literature

A diacetate ketone-catalyzed asymmetric epoxidation of olefins.

Project description:A fructose-derived diacetate ketone has been shown to be an effective catalyst for asymmetric epoxidation. High ee values have been obtained for a variety of trans and trisubstituted olefins including electron-deficient alpha,beta-unsaturated esters as well as certain cis olefins.

| S-EPMC2749516 | biostudies-literature

Kinetic resolution in asymmetric epoxidation using iminium salt catalysis.

Project description:The first reported examples of kinetic resolution in epoxidation reactions using iminium salt catalysis are described, providing up to 99% ee in the epoxidation of racemic cis-chromenes.

| S-EPMC3817536 | biostudies-literature

Iron(II)-Catalyzed Asymmetric Epoxidation of Trisubstituted ?,?-Unsaturated Esters.

Project description:An asymmetric epoxidation of trisubstituted ?,?-unsaturated esters is described. The oxidation utilizes a pseudo-C2-symmetric iron(II) catalyst [Fe(L*)2(CH3CN)(OTf)](OTf) and peracetic acid as oxidant, yielding the ?,?-epoxyesters in high enantiomeric purity (up to 99% ee).

| S-EPMC4486291 | biostudies-literature

Iron-catalyzed asymmetric epoxidation of β,β-disubstituted enones.

Project description:The combination of Fe(OTf)(2) and novel phenanthroline ligands enables the catalytic asymmetric epoxidation of acyclic β,β-disubstituted enones, which have been a heretofore inaccessible substrate class. The reaction provides highly enantioenriched α,β-epoxyketones (up to 92% ee) that can be further converted to functionalized β-ketoaldehydes with an all-carbon quaternary center.

| S-EPMC3116448 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

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