Browse
Submit Data
Databases
API
Help

Dataset Information

27 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Palladium-Catalyzed, Enantioselective Heine Reaction.

ABSTRACT: Aziridines are important synthetic intermediates for the generation of nitrogen-containing molecules. N-Acylaziridines undergo rearrangement by ring expansion to produce oxazolines, a process known as the Heine reaction. The first catalytic, enantioselective Heine reaction is reported for meso-N-acylaziridines where a palladium(II)-diphosphine complex is employed. The highly enantioenriched oxazoline products are valuable organic synthons and potential ligands for transition-metal catalysis.

SUBMITTER: Punk M

PROVIDER: S-EPMC4933940 | biostudies-literature | 2016 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Palladium-Catalyzed, Enantioselective Heine Reaction.

Punk Molly M Merkley Charlotte C Kennedy Katlyn K Morgan Jeremy B JB

ACS catalysis 20160615 7

Aziridines are important synthetic intermediates for the generation of nitrogen-containing molecules. N-Acylaziridines undergo rearrangement by ring expansion to produce oxazolines, a process known as the Heine reaction. The first catalytic, enantioselective Heine reaction is reported for meso-N-acylaziridines where a palladium(II)-diphosphine complex is employed. The highly enantioenriched oxazoline products are valuable organic synthons and potential ligands for transition ...[more]

PMID: 27398262

Similar Datasets

Advancing the mechanistic understanding of an enantioselective palladium-catalyzed alkene difunctionalization reaction.

Project description:The mechanism of an enantioselective palladium-catalyzed alkene difunctionalization reaction has been investigated. Kinetic analysis provides evidence of turnover-limiting attack of a proposed quinone methide intermediate with MeOH and suggests that copper is involved in productive product formation, not just catalyst turnover. Through examination of substrate electronic effects, a Jaffé relationship was observed correlating rate to electronic perturbation at two positions of the substrate. Ligand effects were evaluated to provide evidence of rapid ligand exchange between palladium and copper as well as a correlation between ligand electronic nature and enantioselectivity.

| S-EPMC3066298 | biostudies-literature

Palladium-catalyzed enantioselective 1,1-fluoroarylation of aminoalkenes.

Project description:The development of an enantioselective palladium-catalyzed 1,1-fluoroarylation of unactivated aminoalkenes is described. The reaction uses arylboronic acids as the arene source and Selectfluor as the fluorine source to generate benzylic fluorides in good yields with excellent enantioselectivities. This transformation, likely proceeding through an oxidative Heck mechanism, affords 1,1-difunctionalized alkene products.

| S-EPMC4601482 | biostudies-literature

Palladium-catalyzed enantioselective alkenylation of alkenylbenzene derivatives.

Project description:A regioselective and enantioselective palladium-catalyzed relay Heck alkenylation of alkenylbenzene derivatives to construct remote stereocenters is disclosed. Various β-substituted styrenes were readily obtained in moderate yields with good to excellent levels of enantioselectivity. This strategy provides rapid access to enantioenriched δ, ε, ζ, and η-alkenyl aryl compounds from simple starting materials. Mechanistic studies suggest that termination of the relay reaction is controlled by affinity of the arene for the Pd complex during migration.

| S-EPMC6685350 | biostudies-literature

Palladium-Catalyzed Enantioselective Decarboxylative Allylic Alkylation of Cyclopentanones.

Project description:The first general method for the enantioselective construction of all-carbon quaternary centers on cyclopentanones by enantioselective palladium-catalyzed decarboxylative allylic alkylation is described. Employing the electronically modified (S)-(p-CF3)3-t-BuPHOX ligand, ?-quaternary cyclopentanones were isolated in yields up to >99% with ee's up to 94%. Additionally, in order to facilitate large-scale application of this method, a low catalyst loading protocol was employed, using as little as 0.15 mol % Pd, furnishing the product without any loss in ee.

| S-EPMC4640231 | biostudies-literature

Enantioselective palladium-catalyzed diboration of 1,1-disubstituted allenes.

Project description:A practical and enantioselective palladium-catalyzed diboration of 1,1-disubstituted allenes is developed by employing a P-chiral monophosphorus ligand, BI-DIME. A series of diboronic esters containing a chiral tertiary boronic ester moiety are formed in excellent yields and ee's with the palladium loading as low as 0.2 mol%. DFT calculations revealed a concerted mechanism of oxidative addition of bis(pinacolato)diboron and allene insertion, as well as a critical dispersion effect on the origins of the enantioselectivity. The method is successfully applied to the concise and enantioselective synthesis of brassinazole.

| S-EPMC5615263 | biostudies-literature

Synthesis and preliminary biological studies of 3-substituted indoles accessed by a palladium-catalyzed enantioselective alkene difunctionalization reaction.

Project description:A unique alkene difunctionalization reaction that allows rapid construction of molecular complexity around the biologically relevant indole framework has been developed. The reaction proceeds with up to 87% yield, 99:1 er, and >20:1 dr. Evaluation of several of the compounds revealed promising anticancer activity against MCF-7 cells.

| S-EPMC2896870 | biostudies-literature

Enantioselective palladium-catalyzed [3 + 2] cycloadditions of trimethylenemethane with nitroalkenes.

Project description:Nitroalkenes readily undergo palladium-catalyzed [3 + 2] cycloaddition with trimethylenemethane to generate nitrocyclopentanes in excellent yield and enantioselectivity. Furthermore, the products thus formed are highly versatile synthetic intermediates and provide convenient access to both cyclopentylamines and cyclopentenones.

| S-EPMC3268375 | biostudies-literature

Palladium(II)-catalyzed enantioselective synthesis of 2-vinyl oxygen heterocycles.

Project description:2-Vinylchromanes (1), 2-vinyl-1,4-benzodioxanes (2), and 2,3-dihydro-2-vinyl-2H-1,4-benzoxazines (3) can be prepared in high yields (90-98%) and excellent enantiomeric purities (87-98% ee) by [COP-OAc](2)-catalyzed cyclization of phenolic (E)-allylic trichloroacetimidate precursors. Deuterium-labeling and computational experiments are consistent with these cyclization reactions taking place by an anti-oxypalladation/syn-deoxypalladation mechanism. 2-Vinylchromanes can also be prepared in good yields and high enantiomeric purities from analogous (E)-allylic acetate precursors, which constitutes the first report that acetate is a competent leaving group in COP-catalyzed enantioselective S(N)2' substitution reactions.

| S-EPMC3296363 | biostudies-literature

Palladium(II)-catalyzed highly enantioselective C-H arylation of cyclopropylmethylamines.

Project description:C-H arylation via a Pd(II)/Pd(IV) catalytic cycle has been one of the most extensively studied C-H activation reactions since the 1990s. Despite the rapid development of this reaction in the past two decades, an enantioselective version has not been reported to date. Herein, we report a Pd(II)-catalyzed highly enantioselective (up to 99.5% ee) arylation of cyclopropyl C-H bonds with aryl iodides using mono-N-protected amino acid (MPAA) ligands, providing a new route for the preparation of chiral cis-aryl-cyclopropylmethylamines. The enantiocontrol is also shown to override the diastereoselectivity of chiral substrates.

| S-EPMC4433166 | biostudies-literature

Palladium-Catalyzed Enantioselective Intermolecular Coupling of Phenols and Allylic Alcohols.

Project description:An enantioselective intermolecular coupling of oxygen nucleophiles and allylic alcohols to give β-aryloxycarbonyl compounds is disclosed using a chiral pyridine oxazoline-ligated palladium catalyst under mild conditions. As opposed to the formation of traditional Wacker-type products, enantioselective migratory insertion is followed by β-hydride elimination toward the adjacent alcohol. Deuterium labeling experiments suggest a syn-migratory insertion of the alkene into the Pd-O bond. A broad scope of phenols, various allylic alcohols, and an alkyl hydroperoxide are viable coupling partners in this process.

| S-EPMC5180452 | 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