Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Selective nickel- and manganese-catalyzed decarboxylative cross coupling of some α,β-unsaturated carboxylic acids with cyclic ethers.

ABSTRACT: A nickel- and manganese-catalyzed decarboxylative cross coupling of α, β-unsaturated carboxylic acids with cyclic ethers such as tetrahydrofuran and 1, 4-dioxane was developed. Oxyalkylation was achieved when nickel acetate was used as catalyst, while manganese acetate promoted the reaction of alkenylation.

SUBMITTER: Zhang JX

PROVIDER: S-EPMC4264008 | biostudies-other | 2014

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Rh(III)-catalyzed decarboxylative coupling of acrylic acids with unsaturated oxime esters: carboxylic acids serve as traceless activators.

Project description:?,?-Unsaturated carboxylic acids undergo Rh(III)-catalyzed decarboxylative coupling with ?,?-unsaturated O-pivaloyl oximes to provide substituted pyridines in good yield. The carboxylic acid, which is removed by decarboxylation, serves as a traceless activating group, giving 5-substituted pyridines with very high levels of regioselectivity. Mechanistic studies rule out a picolinic acid intermediate, and an isolable rhodium complex sheds further light on the reaction mechanism.

| S-EPMC3985489 | biostudies-literature

Copper-Catalyzed Decarboxylative Functionalization of Conjugated <i>β,γ</i>-Unsaturated Carboxylic Acids.

Project description:Copper-catalyzed decarboxylative coupling reactions of conjugated β,γ-unsaturated carboxylic acids have been achieved for allylic amination, alkylation, sulfonylation, and phosphinoylation. This approach was effective for a broad scope of amino, alkyl, sulfonyl, and phosphinoyl radical precursors as well as various conjugated β,γ-unsaturated carboxylic acids. These reactions also feature high regioselectivity, good functional group tolerance, and simple operation procedure. Mechanistic studies show that the reaction proceeds via copper-catalyzed electrophilic addition onto an olefin followed by decarboxylation, with radical intermediates involved. These insights present a modular and powerful strategy to access versatilely functionalized allyl-containing skeletons from readily available and stable carboxylic acids.

| S-EPMC8346209 | biostudies-literature

Palladium-Catalyzed Decarboxylative Coupling of Alkynyl Carboxylic Acids with Aryl Tosylates.

Project description:Decarboxylative coupling reactions of alkynyl carboxylic acids with aryl tosylates were developed in the presence of a palladium catalyst. Among the commercially available phosphine ligands, only 1-dicyclohexylphosphino-2-(di-tert-butylphosphino-ethyl)ferrocene (CyPF-tBu) showed good reactivity. The reaction took place smoothly and gave the decarboxylative coupled products in moderate to good yields. This demonstrates the excellent functional group tolerance toward alkyl, alkoxy, fluoro, thiophenyl, ester, and ketone groups. In addition, alkyl-substituted propiolic acids, such as octynoic and hexynoic acids, were coupled with phenyl tosylate to provide the desired products. We found that the electronic properties of the substituents on the phenyl ring in arylpropiolic acids are an important factor. The order of reactivity was found to be aryl iodide > aryl bromide > aryl tosylate > aryl chloride. However, aryl chloride-bearing electron-withdrawing groups showed higher reactivity than those bearing aryl tosylates.

| S-EPMC6644868 | biostudies-literature

Ketones from Nickel-Catalyzed Decarboxylative, Non-Symmetric Cross-Electrophile Coupling of Carboxylic Acid Esters.

Project description:Synthesis of the C-C bonds of ketones relies upon one high-availability reagent (carboxylic acids) and one low-availability reagent (organometallic reagents or alkyl iodides). We demonstrate here a ketone synthesis that couples two different carboxylic acid esters, N-hydroxyphthalimide esters and S-2-pyridyl thioesters, to form aryl alkyl and dialkyl ketones in high yields. The keys to this approach are the use of a nickel catalyst with an electron-poor bipyridine or terpyridine ligand, a THF/DMA mixed solvent system, and ZnCl2 to enhance the reactivity of the NHP ester. The resulting reaction can be used to form ketones that have previously been difficult to access, such as hindered tertiary/tertiary ketones with strained rings and ketones with ?-heteroatoms. The conditions can be employed in the coupling of complex fragments, including a 20-mer peptide fragment analog of Exendin(9-39) on solid support.

| S-EPMC6707838 | biostudies-literature

Merging photoredox and nickel catalysis: decarboxylative cross-coupling of carboxylic acids with vinyl halides.

Project description:Decarboxylative cross-coupling of alkyl carboxylic acids with vinyl halides has been accomplished through the synergistic merger of photoredox and nickel catalysis. This new methodology has been successfully applied to a variety of ?-oxy and ?-amino acids, as well as simple hydrocarbon-substituted acids. Diverse vinyl iodides and bromides give rise to vinylation products in high efficiency under mild, operationally simple reaction conditions.

| S-EPMC4308738 | biostudies-literature

Cobalt-catalyzed highly enantioselective hydrogenation of ?,?-unsaturated carboxylic acids.

Project description:Asymmetric hydrogenation of ?,?-unsaturated acids catalyzed by noble metals has been well established, whereas, the asymmetric hydrogenation with earth-abundant-metal was rarely reported. Here, we describe a cobalt-catalyzed asymmetric hydrogenation of ?,?-unsaturated carboxylic acids. By using chiral cobalt catalyst bearing electron-donating diphosphine ligand, high activity (up to 1860 TON) and excellent enantioselectivity (up to >99% ee) are observed. Furthermore, the cobalt-catalyzed asymmetric hydrogenation is successfully applied to a broad spectrum of ?,?-unsaturated carboxylic acids, such as various ?-aryl and ?-alkyl cinnamic acid derivatives, ?-oxy-functionalized ?,?-unsaturated acids, ?-substituted acrylic acids and heterocyclic ?,?-unsaturated acids (30 examples). The synthetic utility of the protocol is highlighted by the synthesis of key intermediates for chiral drugs (6 cases). Preliminary mechanistic studies reveal that the carboxy group may be involved in the control of the reactivity and enantioselectivity through an interaction with the metal centre.

| S-EPMC7319995 | biostudies-literature

Nickel-Catalyzed Conversion of Amides to Carboxylic Acids.

Project description:We report the conversion of amides to carboxylic acids using nonprecious metal catalysis. The methodology strategically employs a nickel-catalyzed esterification using 2-(trimethylsilyl)ethanol, followed by a fluoride-mediated deprotection in a single-pot operation. This approach circumvents catalyst poisoning observed in attempts to directly hydrolyze amides using nickel catalysis. The selectivity and mildness of this transformation are shown through competition experiments and the net-hydrolysis of a complex valine-derived substrate. This strategy addresses a limitation in the field with regard to functional groups accessible from amides using transition metal-catalyzed C-N bond activation and should prove useful in synthetic applications.

| S-EPMC7184625 | biostudies-literature

Quaternary Centers by Nickel-Catalyzed Cross-Coupling of Tertiary Carboxylic Acids and (Hetero)Aryl Zinc Reagents.

Project description:This work bridges a gap in the cross-coupling of aliphatic redox-active esters with aryl zinc reagents. Previously limited to primary, secondary, and specialized tertiary centers, a new protocol has been devised to enable the coupling of general tertiary systems using nickel catalysis. The scope of this operationally simple method is broad, and it can be used to simplify the synthesis of medicinally relevant motifs bearing quaternary centers.

| S-EPMC6391118 | biostudies-literature

Synthesis of aryldifluoromethyl aryl ethers via nickel-catalyzed suzuki cross-coupling between aryloxydifluoromethyl bromides and boronic acids.

Project description:As a unique organofluorine fragment, gem-difluoromethylated motifs have received widespread attention. Here, a convenient and efficient synthesis of aryldifluoromethyl aryl ethers (ArCF2OAr') was established via Nickel-catalyzed aryloxydifluoromethylation with arylboronic acids. This approach features easily accessible starting materials, good tolerance of functionalities, and mild reaction conditions. Diverse late-stage difluoromethylation of many pharmaceuticals and natural products were readily realized. Notably, a new difluoromethylated PD-1/PD-L1 immune checkpoint inhibitor was conveniently synthesized and showed both improved metabolic stability and enhanced antitumor efficacy. Preliminary mechanistic studies suggested the involvement of a Ni(I/III) catalytic cycle.

| S-EPMC9814959 | biostudies-literature

CuH-Catalyzed Asymmetric Reduction of ?,?-Unsaturated Carboxylic Acids to ?-Chiral Aldehydes.

Project description:The copper hydride (CuH)-catalyzed enantioselective reduction of ?,?-unsaturated carboxylic acids to saturated aldehydes is reported. This protocol provides a new method to access a variety of ?-chiral aldehydes in good yields, with high levels of enantioselectivity and broad functional group tolerance. A reaction pathway involving a ketene intermediate is proposed based on preliminary mechanistic studies and density functional theory calculations.

| S-EPMC5800953 | 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