Browse
Submit Data
Databases
API
Help

Dataset Information

27 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

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

ABSTRACT: 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.

SUBMITTER: Dai HX

PROVIDER: S-EPMC3685289 | biostudies-literature | 2013 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

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

Dai Hui-Xiong HX Li Gang G Zhang Xing-Guo XG Stepan Antonia F AF Yu Jin-Quan JQ

Journal of the American Chemical Society 20130508 20

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 ...[more]

PMID: 23614807

Similar Datasets

Pd(ii)-catalyzed remote regiodivergent ortho- and meta-C-H functionalizations of phenylethylamines.

Project description:Site selectivity control is of vital importance in the direct functionalization of inert C-H bonds. Reported here is a novel example of remote regiodivergent ortho- and meta-C-H bond functionalizations of phenylethylamine derivatives by using a novel 2-cyanobenzoyl group as the original directing functionality, where the regioselectivity was adjusted by a methylation. The potential of the method was exemplified by sequential functionalizations of both ortho- and meta-C-H bonds of a phenylethylamine derivative in a streamlined manner.

| S-EPMC5949857 | biostudies-other

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

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

Project description: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.

| S-EPMC2667208 | biostudies-literature

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

Urea-Substituted Tetramethylcyclopentadienyl Ligands for Supramolecularly Accelerated Rh<sup>III</sup> -Catalyzed ortho-C-H Olefination of Benzoic Acid Derivatives.

Project description:The design and synthesis of air-stable and conveniently crystallizable RhIII -cyclopentadienyl catalysts substituted with a urea moiety, which are able to accelerate the C-H olefination of benzoic acid derivatives, is reported. Through kinetic studies and NMR titration experiments, the catalysts' substrate recognition ability mediated by hydrogen bonding was identified to be the reason for this effect. Introduction of pyridone-phosphine ligands capable of forming additional H-bond interactions increased the catalytic performance even further. By unveiling a proportionality between reaction rate and relative complex formation enthalpy the hypothesis of a supramolecular catalyst preformation was supported. Its application to a variety of substrates proved the catalyst system's advantages, generally increasing the yields when compared to the results obtained with widely used [RhCp*Cl2 ]2 .

| S-EPMC7898290 | 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

Ether-directed ortho-C-H olefination with a palladium(II)/monoprotected amino acid catalyst.

Project description: Not available

| S-EPMC3786684 | biostudies-literature

Pd(II)-catalysed meta-C-H functionalizations of benzoic acid derivatives.

Project description:Benzoic acids are highly important structural motifs in drug molecules and natural products. Selective C-H bond functionalization of benzoic acids will provide synthetically useful tools for step-economical organic synthesis. Although direct ortho-C-H functionalizations of benzoic acids or their derivatives have been intensely studied, the ability to activate meta-C-H bond of benzoic acids or their derivatives in a general manner via transition-metal catalysis has been largely unsuccessful. Although chelation-assisted meta-C-H functionalization of electron-rich arenes was reported, chelation-assisted meta-C-H activation of electron-poor arenes such as benzoic acid derivatives remains a formidable challenge. Herein, we report a general protocol for meta-C-H olefination of benzoic acid derivatives using a nitrile-based sulfonamide template. A broad range of benzoic acid derivatives are meta-selectively olefinated using molecular oxygen as the terminal oxidant. The meta-C-H acetoxylation, product of which is further transformed at the meta-position, is also reported.

| S-EPMC4737847 | biostudies-other

Pd(II)-catalyzed ortho arylation of 2-arylbenzothiazoles with aryl iodides via benzothiazole-directed C-H activation.

Project description:A novel and efficient method for the arylation of 2-arylbenzothiazoles is described via C-H activation. The desired C(Ar)-C(Ar) bond formation proceeded efficiently with good functional-group tolerance and high regioselectivity. Proposed mechanism for the arylation of 2-arylbenzothiazole is depicted.

| S-EPMC3363328 | 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