Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Metal π-Lewis base activation in palladium(0)-catalyzed trans-alkylative cyclization of alkynals.

ABSTRACT: The Pd(0)-mediated umpolung reaction of an alkyne to achieve trans-difunctionalization is a potential synthetic methodology, but its insightful activation mechanism of Pd(0)-alkyne interaction has yet to be established. Here, a Pd(0)-π-Lewis base activation mode is proposed and investigated by combining theoretical and experimental studies. In this activation mode, the Pd(0) coordinates to the alkyne group and enhances its nucleophilicity through π-back-donation, facilitating the nucleophilic attack on the aldehyde to generate a trans-Pd(ii)-vinyl complex. Ligand-effect studies reveal that the more electron-donating one would accelerate the reaction, and the cyclization of the challenging flexible C- or O-tethered substrates has been realized. The origin of regioselectivities is also explicated by the newly proposed metal π-Lewis base activation mode.

SUBMITTER: Zhu L

PROVIDER: S-EPMC11323327 | biostudies-literature | 2024 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Metal π-Lewis base activation in palladium(0)-catalyzed <i>trans</i>-alkylative cyclization of alkynals.

Zhu Lei L Zhao Bo B Xie Ke K Gui Wu-Tao WT Niu Sheng-Li SL Zheng Peng-Fei PF Chen Ying-Chun YC Qi Xiao-Wei XW Ouyang Qin Q

Chemical science 20240718 32

The Pd(0)-mediated umpolung reaction of an alkyne to achieve <i>trans</i>-difunctionalization is a potential synthetic methodology, but its insightful activation mechanism of Pd(0)-alkyne interaction has yet to be established. Here, a Pd(0)-π-Lewis base activation mode is proposed and investigated by combining theoretical and experimental studies. In this activation mode, the Pd(0) coordinates to the alkyne group and enhances its nucleophilicity through π-back-donation, facilitating the nucleoph ...[more]

PMID: 39148807

Similar Datasets

A metal π-Lewis base activation model for Pd-catalyzed hydroamination of amines and 1,3-dienes.

Project description:As a general mechanism proposal, a Pd(ii)-H migration insertion process is not able to well explicate the Pd-catalyzed hydroamination of amines and 1,3-dienes. Here we demonstrate that 1,3-dienes form electron-neutral and HOMO-raised η2-complexes with Pd(0) via π-Lewis base activation, which undergoes protonation with a variety of acidic sources, such as Brønsted acids, Lewis acid-activated indazoles, and Pd(ii) pre-catalyst triggered ammonium salts. The resultant π-allyl palladium complexes undergo the amination reaction to give the final observed products. FMO and NPA analyses have revealed the nature of Pd(0) mediated π-Lewis base activation of 1,3-dienes. The calculation results show that the π-Lewis base activation pathway is more favourable than the Pd(ii)-H species involved one in different reactions. Further control experiments corroborated our mechanistic proposal, and an efficient Pd(0) mediated hydroamination reaction was developed.

| S-EPMC10155909 | biostudies-literature

π-π stacking assisted regioselectivity regulation in palladium-catalyzed cyclization reactions: a theoretical study.

Project description:The regulation of regioselectivity is an objective often pursued by organic chemists, and the comprehension of its mechanisms is crucial for devising efficient synthetic pathways. In this report, we conducted theoretical calculations to explore the regioselectivity regulatory mechanisms of two palladium-catalyzed cyclization reactions. In these cyclization reactions, manipulating the structural differences in the reaction substrates leads to the formation of distinct products. A detailed reaction mechanism and reactivity profile for this reaction were revealed. Furthermore, a π-π stacking assisted regioselectivity regulatory mechanism was proven by distortion-interaction energy analysis and noncovalent interaction calculations. The calculated results presented herein provide a theoretical guide for further experimental investigations of regioselectivity regulation.

| S-EPMC11615657 | biostudies-literature

Synthesis of bicyclic ethers by a palladium-catalyzed oxidative cyclization-redox relay-π-allyl-Pd cyclization cascade reaction.

Project description:Bicyclic ether scaffolds are found in a variety of natural products and are of interest in probe and drug discovery. A palladium-catalyzed cascade reaction has been developed to provide efficient access to these scaffolds from readily available linear diene-diol substrates. A Pd redox-relay process is used strategically to transmit reactivity between an initial oxypalladative cyclization and a subsequent π-allyl-Pd cyclization at remote sites. The reaction affords a variety of bicyclic ether scaffolds with complete diastereoselectivity for cis-ring fusion.

| S-EPMC6601619 | biostudies-literature

Cooperative Chiral Lewis Base/Palladium-Catalyzed Asymmetric Syntheses of Methylene-Containing δ-Lactams.

Project description:We herein report a two-step approach for the enantioselective synthesis of novel chiral δ-lactams. By using a cooperative chiral ITU/achiral Pd-catalyst system, this protocol proceeds via an asymmetric α-allylation of activated aryl esters first, followed by an acid-mediated lactam formation. A variety of differently substituted products could be obtained with usually high levels of enantioselectivities and in reasonable yields (16 examples, up to 98 : 2 er and 73 % yield over two steps). In addition, further utilizations of the products via transformations of the exocyclic double bond were successfully carried out as well.

| S-EPMC11005102 | biostudies-literature

Palladium(0)-catalyzed arylative dearomatization of phenols.

Project description:The palladium-catalyzed arylative dearomatization of phenols to yield spirocyclohexadienone products in good to excellent yields has been developed. Preliminary results demonstrate that the formation of the spirocyclic all-carbon quaternary center can be accomplished with high levels of enantiocontrol (up to 91% ee).

| S-EPMC3124856 | biostudies-literature

Electrochemical Palladium-Catalyzed Oxidative Carbonylation-Cyclization of Enallenols.

Project description:Herein, we report an electrochemical oxidative palladium-catalyzed carbonylation-carbocyclization of enallenols to afford γ-lactones and spirolactones, which proceeds with excellent chemoselectivity. Interestingly, electrocatalysis was found to have an accelerating effect on the rate of the tandem process, leading to a more efficient reaction than that under chemical redox conditions.

| S-EPMC10098644 | biostudies-literature

Enantioselective, Lewis Base-Catalyzed Sulfenocyclization of Polyenes.

Project description:A sulfenium-ion-initiated, catalytic, enantioselective polyene cyclization is described. Homogeranylarenes and ortho-geranylphenols undergo polycyclization in good yield, diastereoselectivity, and enantioselectivity. The stereodetermining step is the generation of an enantiomerically enriched thiiranium ion from a terminal alkene and a sulfenylating agent in the presence of a chiral Lewis basic catalyst. The use of hexafluoroisopropyl alcohol as the solvent is crucial to obtain good yields. The thioether moiety resulting from the reaction can be subsequently transformed into diverse oxygen and carbon functionality postcyclization. The utility of this method is demonstrated by the enantioselective syntheses of (+)-ferruginol and (+)-hinokiol.

| S-EPMC6008787 | biostudies-literature

Palladium-catalyzed dehydrogenative C-H cyclization for isoindolinone synthesis.

Project description:In this paper Pd-catalyzed intramolecular dehydrogenative C(sp3)-H amidation for the synthesis of isoindolinones is described. This method features the use of a Pd/C catalyst and the addition of a stoichiometric amount of oxidant is not necessary. A mechanistic study suggested the possible formation of H2 gas during the reaction.

| S-EPMC9037686 | 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-literature

Long-Range Olefin Isomerization Catalyzed by Palladium(0) Nanoparticles.

Project description:Long-range olefin isomerization of 2-alkenylbenzoic acid derivatives going through two to five sp3-carbon atoms to give (E)-alkenes was achieved with palladium(0) nanoparticles. The substrate scope of this reaction includes carboxylic acid, ester, and primary to tertiary amides and tolerates various substituents on the benzene ring. This isomerization reaction was catalyzed by recyclable Pd(0) nanoparticles, prepared in situ from PdCl2 and characterized by X-ray powder diffraction and scanning electron microscopy analyses. 1H NMR studies and kinetic modeling supported a stepwise process. This new process was applied to synthesize a natural dihydroisocoumarin with good efficiency.

| S-EPMC6640945 | 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