Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Pd(II)-catalyzed olefination of electron-deficient arenes using 2,6-dialkylpyridine ligands.

ABSTRACT: Pd(II)-catalyzed meta-olefination of highly electron-deficient arenes is achieved through the use of a rationally designed mutually repulsive ligand. The combination of directed and nondirected C-H functionalization of arenes provides a versatile route for the synthesis of highly sought after 1,2,4-trisubstituted arenes.

SUBMITTER: Zhang YH

PROVIDER: S-EPMC2667208 | biostudies-literature | 2009 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Pd(II)-catalyzed olefination of electron-deficient arenes using 2,6-dialkylpyridine ligands.

Zhang Yang-Hui YH Shi Bing-Feng BF Yu Jin-Quan JQ

Journal of the American Chemical Society 20090401 14

Pd(II)-catalyzed meta-olefination of highly electron-deficient arenes is achieved through the use of a rationally designed mutually repulsive ligand. The combination of directed and nondirected C-H functionalization of arenes provides a versatile route for the synthesis of highly sought after 1,2,4-trisubstituted arenes. ...[more]

PMID: 19296661

Similar Datasets

Pd(II)-catalyzed hydroxyl-directed C-H olefination enabled by monoprotected amino acid ligands.

Project description:A novel Pd(II)-catalyzed ortho-C-H olefination protocol has been developed using spatially remote, unprotected tertiary, secondary, and primary alcohols as the directing groups. Mono-N-protected amino acid ligands were found to promote the reaction, and an array of olefin coupling partners could be used. When electron-deficient alkenes were used, the resulting olefinated intermediates underwent subsequent Pd(II)-catalyzed oxidative intramolecular cyclization to give the corresponding pyran products, which could be converted into ortho-alkylated alcohols under hydrogenolysis conditions. The mechanistic details of the oxidative cyclization step are discussed and situated in the context of the overall catalytic cycle.

| S-EPMC2882203 | biostudies-literature

Pd(II)-catalyzed olefination of sp3 C-H bonds.

Project description:The first Pd(II)-catalyzed sp(3) C-H olefination reaction has been developed using N-arylamide directing groups. Following olefination, the resulting intermediates were found to undergo rapid 1,4-addition to give the corresponding gamma-lactams. Notably, this method was effective with substrates containing alpha-hydrogen atoms and could be applied to effect methylene C-H olefination of cyclopropane substrates.

| S-EPMC2841429 | biostudies-literature

Pd(II)-catalyzed enantioselective C-H olefination of diphenylacetic acids.

Project description:Pd(II)-catalyzed enantioselective C-H olefination of diphenylacetic acid substrates has been achieved through the use of monoprotected chiral amino acid ligands. The absolute configuration of the resulting olefinated products is consistent with that of a proposed C-H insertion intermediate.

| S-EPMC2806936 | biostudies-literature

Diindenopyrazines: Electron-Deficient Arenes.

Project description:The syntheses, properties and application of the air-stable electron acceptors, diindenopyrazines 4 a-g are reported demonstrating the introduction of functional aryl groups in the 6- and 12-positions. The targets are accessible on the hundred milligram to gram scale. The structure of the aryl groups in 4 a-g modulates their solubility, redox potentials and optical properties. The introduction of electron-poor aryl groups to the electron-poor diindenopyrazine backbone reduces the electron affinity to -4 eV, making the compounds attractive as n-semiconductors. A simple organic field-effect transistor of 4 e -without optimization- shows electron transport with a mobility of up to 0.037 cm2 V-1 s-1 .

| S-EPMC8361971 | biostudies-literature

Pd(II)-catalyzed ortho- or meta-C-H olefination of phenol derivatives.

Project description:A combination of weakly coordinating auxiliaries and ligand acceleration allows for the development of both ortho- and meta-selective C-H olefination of phenol derivatives. These reactions demonstrate the feasibility of directing C-H functionalizations when functional groups are distal to target C-H bonds. The meta-C-H functionalization of electron-rich phenol derivatives is unprecedented and orthogonal to previous electrophilic substitution of phenols in terms of regioselectivity. These methods are also applied to functionalize ?-phenoxyacetic acids, a fibrate class of drug scaffolds.

| S-EPMC3685289 | biostudies-literature

Pd(II)-catalyzed para-selective C-H arylation of monosubstituted arenes.

Project description:Pd-catalyzed highly para-selective C-H arylation of monosubstituted arenes (including toluene) is developed for the first time using an F(+) reagent as a bystanding oxidant. This finding provides a new retrosynthetic disconnection for para-substituted biaryl synthesis via C-H/C-H cross-coupling.

| S-EPMC3345815 | biostudies-literature

Pd(II)-Catalyzed C3-Selective Arylation of Pyridine with (Hetero)arenes.

Project description:Palladium catalyzed, nondirected C3-selective arylation of pyridines with arenes and heteroarenes in the presence of 1,10-phenanthroline as the ligand has been developed. The optimized conditions allow for a highly C3-selective arylation of pyridines, affording various 3,3'-bipyridines and 3-arylpyridines.

| S-EPMC4821414 | biostudies-literature

Pd-catalyzed aerobic oxidative coupling of arenes: evidence for transmetalation between two Pd(II)-aryl intermediates.

Project description:Pd-catalyzed aerobic oxidative coupling of arenes provides efficient access to biaryl compounds. The biaryl product forms via C-H activation of two arenes to afford a Pd(II)ArAr' intermediate, which then undergoes C-C reductive elimination. The key Pd(II)ArAr' intermediate could form via a "monometallic" pathway involving sequential C-H activation at a single Pd(II) center, or via a "bimetallic" pathway involving parallel C-H activation at separate Pd(II) centers, followed by a transmetalation step between two Pd(II)-aryl intermediates. Here, we investigate the oxidative coupling of o-xylene catalyzed by a PdX2/2-fluoropyridine catalyst (X = trifluoroacetate, acetate). Kinetic studies, H/D exchange experiments, and kinetic isotope effects provide clear support for a bimetallic/transmetalation mechanism.

| S-EPMC4161672 | biostudies-literature

Kinetic resolution of sulfur-stereogenic sulfoximines by Pd(ii)-MPAA catalyzed C-H arylation and olefination.

Project description:A direct Pd(ii)-catalyzed kinetic resolution of heteroaryl-enabled sulfoximines through an ortho-C-H alkenylation/arylation of arenes has been developed. The coordination of the sulfoximine pyridyl-motif and the chiral amino acid MPAA ligand to the Pd(ii)-catalyst controls the enantio-discriminating C(aryl)-H activation. This method provides access to a wide range of enantiomerically enriched unreacted aryl-pyridyl-sulfoximine precursors and C(aryl)-H alkenylation/arylation products in good yields with high enantioselectivity (up to >99% ee), and selectivity factor up to >200. The coordination preference of the directing group, ligand effect, geometry constraints, and the transient six-membered concerted-metalation-deprotonation species dictate the stereoselectivity; DFT studies validate this hypothesis.

| S-EPMC8597855 | biostudies-literature

Silver-Catalyzed Aldehyde Olefination Using Siloxy Alkynes.

Project description:We describe the development of a silver-catalyzed carbonyl olefination employing electron rich siloxy alkynes. This process constitutes an efficient synthesis of trisubstituted unsaturated esters, and represents an alternative to the widely utilized Horner-Wadsworth-Emmons reaction. Excellent diastereoselectivities are observed for a range of aldehydes using either 1-siloxy-1-propyne or 1-siloxy-1-hexyne. This mild catalytic process also enables chemoselective olefination of aldehydes in the presence of either ester or ketone functionality. Furthermore, since no by-products are generated, this catalytic process is perfectly suited for development of sequential reactions that can be carried out in a single flask.

| S-EPMC3837490 | 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