Browse
Submit Data
Databases
API
Help

Dataset Information

22 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Enantioselective epoxidation of nonconjugated cis-olefins by chiral dioxirane.

ABSTRACT: 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.

SUBMITTER: Burke CP

PROVIDER: S-EPMC2783705 | biostudies-literature | 2009 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Enantioselective epoxidation of nonconjugated cis-olefins by chiral dioxirane.

Burke Christopher P CP Shi Yian Y

Organic letters 20091101 22

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. ...[more]

PMID: 19824657

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

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

Project description: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.

| S-EPMC2784290 | biostudies-literature

Asymmetric total synthesis of (-)-plicatic acid via a highly enantioselective and diastereoselective nucleophilic epoxidation of acyclic trisubstitued olefins.

Project description:The first total synthesis of (-)-plicatic acid has been achieved by a concise and enantioselective route. In this synthesis, a conceptually new strategy featuring an asymmetric epoxidation-intramolecular epoxy-ring-opening Friedel-Crafts reaction sequence was developed for the stereoselective construction of the 2,7'-cyclolignane skeleton bearing contiguous quaternary-quaternary-tertiary stereocenters. The implementation of this strategy was enabled by the development of a modified protocol for the Seebach epoxidation with TADOOH, which affords an unprecedented, highly enantioselective and diastereoselective epoxidation with a range of alpha-carbonyl-beta-substituted acrylates 3.

| S-EPMC2755215 | biostudies-other

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

Enantioselective Allylic C-H Oxidation of Terminal Olefins to Isochromans by Palladium(II)/Chiral Sulfoxide Catalysis.

Project description:The enantioselective synthesis of isochroman motifs has been accomplished by palladium(II)-catalyzed allylic C-H oxidation from terminal olefin precursors. Critical to the success of this goal was the development and utilization of a novel chiral aryl sulfoxide-oxazoline (ArSOX) ligand. The allylic C-H oxidation reaction proceeds with the broadest scope and highest levels of asymmetric induction reported to date (avg. 92?% ee, 13 examples with greater than 90?% ee).

| S-EPMC5729747 | biostudies-literature

Regio- and enantioselective catalytic monoepoxidation of conjugated dienes: synthesis of chiral allylic cis-epoxides.

Project description:Ti(IV)-salan 4 catalyzes the diastereo- and enantioselective monoepoxidation of conjugated dienes using 30% H2O2 at rt or below even in the presence of other olefins and adjacent stereocenters. Its enantiomer, ent-4, provides access to the opposite diastereomer or enantiomer. The resultant chiral allylic epoxides, and the triols derived from them, are versatile synthetic intermediates as well as substructures present in many bioactive natural products. The epoxidation is highly specific for Z-olefins. For 1-acyl(silyl)oxypenta-2,4-dienes, epoxidation of the distal olefin is generally favored in contrast to the adjacent regioselectivity characteristic of Sharpless, peracid, and other directed epoxidations of hydroxylated dienes.

| S-EPMC4342986 | biostudies-literature

Catalytic, Enantioselective ?-Alkylation of Azlactones with Nonconjugated Alkenes by Directed Nucleopalladation.

Project description:A palladium(II)-catalyzed enantioselective ?-alkylation of azlactones with nonconjugated alkenes is described. The reaction employs a chiral BINOL-derived phosphoric acid as the source of stereoinduction, and a cleavable bidentate directing group appended to the alkene to control the regioselectivity and stabilize the nucleopalladated alkylpalladium(II) intermediate in the catalytic cycle. A wide range of azlactones were found to be compatible under the optimal reaction conditions to afford products bearing ?,?-disubstituted ?-amino-acid derivatives with high yields and high enantioselectivity.

| S-EPMC6595491 | biostudies-literature

Catalytic, enantioselective, intramolecular carbosulfenylation of olefins.

Project description:The first catalytic, enantioselective carbosulfenylation of alkenes with an aromatic nucleophile is described, using a BINAM-based selenophosphoramide catalyst. E-Alkyl- and aryl-substituted alkenes afforded tetrahydronaphthalenes with complete diastereospecificity, and generally high enantiomeric ratios.

| S-EPMC3675264 | biostudies-literature

Lewis base catalyzed, enantioselective, intramolecular sulfenoamination of olefins.

Project description:A method for the enantioselective, intramolecular sulfenoamination of various olefins has been developed using a chiral BINAM-based selenophosphoramide, Lewis base catalyst. Terminal and trans disubstituted alkenes afforded pyrrolidines, piperidines, and azepanes in high yields and high enantiomeric ratios via enantioselective formation and subsequent stereospecific capture of the thiiranium intermediate with the pendant tosyl-protected amine.

| S-EPMC4073881 | biostudies-other

A peptide-embedded trifluoromethyl ketone catalyst for enantioselective epoxidation.

Project description:The development of peptide-based oxidation catalysts that use a transiently generated dioxirane as the chemically active species is reported. The active catalyst is a chiral trifluoromethyl ketone (Tfk) with a pendant carboxylic acid that can be readily incorporated into a peptide. These peptides were capable of epoxidizing alkenes in high yield (up to 89%) and enantiomeric ratios (er) ranging from 69.0:31.0 to 91.0:9.0, depending on the alkene substitution pattern.

| S-EPMC3288446 | 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