Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Access to electron-rich arene-fused hexahydroquinolizinones through a gold-catalysis-initiated cascade process.

ABSTRACT: Golden Cascade: With a tethered, electron-rich arene as the internal nucleophile, a gold-catalyzed amide cyclization to an alkyne initiates a cascade process that ends with a Ferrier rearrangement. Electron-rich arene-bearing hexahydroquinolizin-2-ones are formed in good yields and can be converted into indole alkaloids in only a few steps.

SUBMITTER: Liu L

PROVIDER: S-EPMC3438900 | biostudies-other | 2012 Jul

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Publications

Access to electron-rich arene-fused hexahydroquinolizinones through a gold-catalysis-initiated cascade process.

Liu Lianzhu L Zhang Liming L

Angewandte Chemie (International ed. in English) 20120612 29

Golden Cascade: With a tethered, electron-rich arene as the internal nucleophile, a gold-catalyzed amide cyclization to an alkyne initiates a cascade process that ends with a Ferrier rearrangement. Electron-rich arene-bearing hexahydroquinolizin-2-ones are formed in good yields and can be converted into indole alkaloids in only a few steps. ...[more]

PMID: 22692916

Similar Datasets

One-pot synthesis of fused pyrroles through a key gold-catalysis-triggered cascade.

Project description:A two-step, one-pot synthesis of fused pyrroles is realized by firstly condensing an N-alkynylhydroxammonium salt with a readily enolizable ketone under mild basic conditions and then subjecting the reaction mixture to a gold catalyst, which triggers a cascade reaction involving a facile initial [3.3]-sigmatropic rearrangement of the gold-catalysis product, that is, an N,O-dialkenylhydroxamine. The reaction provides a facile access to polycyclic pyrroles in moderate to good yields.

| S-EPMC4098939 | biostudies-literature

Palladium-catalyzed intramolecular carbopalladation/cyclization cascade: access to polycyclic N-fused heterocycles.

Project description:An efficient palladium-catalyzed intramolecular carbopalladation/cyclization cascade toward tetra- and pentacyclic N-fused heterocycles has been developed. This transformation proceeds via the palladium-catalyzed coupling of aryl halides with internal propargylic esters or ethers followed by the 5-endo-dig cyclization leading to polycyclic pyrroloheterocycles in moderate to excellent yields.

| S-EPMC3131228 | biostudies-literature

Pyridinylidenaminophosphines: Facile Access to Highly Electron-Rich Phosphines.

Project description:Electron-rich tertiary phosphines are valuable species in chemical synthesis. However, their broad application as ligands in catalysis and reagents in stoichiometric reactions is often limited by their costly synthesis. Herein, we report the synthesis and properties of a series of phosphines with 1-alkylpyridin-4-ylidenamino and 1-alkylpyridin-2-ylidenamino substituents that are accessible in a very short and scalable route starting from commercially available aminopyridines and chlorophosphines. The determination of the Tolman electronic parameter (TEP) value reveals that the electron donor ability can be tuned by the substituent pattern at the aminopyridine backbone and it can exceed that of common alkylphosphines and N-heterocyclic carbenes. The potential of the new phosphines as strong nucleophiles in phosphine-mediated transformations is demonstrated by the formation of Lewis base adducts with CO2 and CS2 . In addition, the coordination chemistry of the new phosphines towards CuI , AuI , and PdII metal centers has been explored, and a convenient procedure to introduce the most basic phosphine into metal complexes starting from air-stable phosphonium salt is described.

| S-EPMC6972615 | biostudies-literature

Triple the fun: tris(ferrocenyl)arene-based gold(i) complexes for redox-switchable catalysis.

Project description:The modular syntheses of C 3-symmetric tris(ferrocenyl)arene-based tris-phosphanes and their homotrinuclear gold(i) complexes are reported. Choosing the arene core allows fine-tuning of the exact oxidation potentials and thus tailoring of the electrochemical response. The tris[chloridogold(i)] complexes were investigated in the catalytic ring-closing isomerisation of N-(2-propyn-1-yl)benzamide, showing cooperative behaviour vs. a mononuclear chloridogold(i) complex. Adding one, two, or three equivalents of 1,1'-diacetylferrocenium[tetrakis(perfluoro-tert-butoxy)aluminate] as an oxidant during the catalytic reaction (in situ) resulted in a distinct, stepwise influence on the resulting catalytic rates. Isolation of the oxidised species is possible, and using them as (pre-)catalysts (ex situ oxidation) confirmed the activity trend. Proving the intactness of the P-Au-Cl motif during oxidation, the tri-oxidised benzene-based complex has been structurally characterised.

| S-EPMC8162263 | biostudies-literature

Bifunctional Phosphine Ligand Enabled Gold-Catalyzed Alkynamide Cycloisomerization: Access to Electron-Rich 2-Aminofurans and Their Diels-Alder Adducts.

Project description:By using biphenyl-2-ylphosphines functionalized with a remote tertiary amino group as a ligand, readily available acetylenic amides are directly converted into 2-aminofurans devoid of any electron-withdrawing and hence deactivating/stabilizing substituents. These highly electron-rich furans have rarely been prepared, let alone applied in synthesis, because of their high reactivities and low stabilities associated with the electron-rich nature of the furan ring. In this work, these reactive furans smoothly undergo either in situ intermolecular Diels-Alder reactions to deliver highly functionalized/substituted aniline products or intramolecular ones to furnish carbazole-4-carboxylates in mostly good to excellent yields. This work offers general and expedient access to this class of little studies electron-rich furans and should lead to exciting opportunities for their applications.

| S-EPMC7173349 | biostudies-literature

Access to Spirooxindole-Fused Cyclopentanes via a Stereoselective Organocascade Reaction Using Bifunctional Catalysis.

Project description:The present study reports an asymmetric organocascade reaction of oxindole-derived alkenes with 3-bromo-1-nitropropane efficiently catalyzed by the bifunctional catalyst. Spirooxindole-fused cyclopentanes were produced in moderate-to-good isolated yields (15-69%) with excellent stereochemical outcomes. The synthetic utility of the protocol was exemplified on a set of additional transformations of the corresponding spirooxindole compounds.

| S-EPMC10278142 | biostudies-literature

A Desulfonylative Approach in Oxidative Gold Catalysis: Regiospecific Access to Donor-Substituted Acyl Gold Carbenes.

Project description:Donor-substituted acyl gold carbenes are challenging to access selectively by gold-promoted intermolecular oxidation of internal alkynes as the opposite regioisomers frequently predominate. By using alkynyl sulfones or sulfonates as substrates, the oxidative gold catalysis in the presence of substituted pyridine N-oxides offers regiospecific access to acyl/aryl, acyl/alkenyl, and acyl/alkoxy gold carbenes by in situ expulsion of sulfur dioxide. The intermediacies of these reactive species are established by their reactivities, including undergoing further oxidation by the same oxidant, cyclopropanation of styrenes, engaging in a [3+2] cycloaddition with ?-methylstyrene, and conversion into dienones.

| S-EPMC6035048 | biostudies-literature

Access to benzo-fused nine-membered heterocyclic alkenes with a trifluoromethyl carbinol moiety via a double decarboxylative formal ring-expansion process under palladium catalysis.

Project description:Direct access to pharmaceutically attractive benzo-fused nine-membered heterocyclic alkenes 3 with a trifluoromethyl carbinol moiety was achieved via a palladium-catalyzed double-decarboxylative formal ring-expansion process from six-membered trifluoromethyl benzo[d][1,3]oxazinones 1 to nine-membered trifluoromethyl benzo[c][1,5]oxazonines 3 in the presence of vinylethylene carbonates 2. Generation of a Pd-?-allyl zwitterionic intermediate was proposed in the catalytic cycle. The trifluoromethyl group in the benzoxazinanones 1 plays an important role throughout the transformation. Diastereoselective chemical transformations of products 3 were also demonstrated.

| S-EPMC5915791 | biostudies-literature

Gold Redox Catalysis through Base-Initiated Diazonium Decomposition toward Alkene, Alkyne, and Allene Activation.

Project description:The discovery of photoassisted diazonium activation toward gold(I) oxidation greatly extended the scope of gold redox catalysis by avoiding the use of a strong oxidant. Some practical issues that limit the application of this new type of chemistry are the relative low efficiency (long reaction time and low conversion) and the strict reaction condition control that is necessary (degassing and inert reaction environment). Herein, an alternative photofree condition has been developed through Lewis base induced diazonium activation. With this method, an unreactive AuI catalyst was used in combination with Na2 CO3 and diazonium salts to produce a AuIII intermediate. The efficient activation of various substrates, including alkyne, alkene and allene was achieved, followed by rapid AuIII reductive elimination, which yielded the C-C coupling products with good to excellent yields. Relative to the previously reported photoactivation method, our approach offered greater efficiency and versatility through faster reaction rates and broader reaction scope. Challenging substrates such as electron rich/neutral allenes, which could not be activated under the photoinitiation conditions (<5 % yield), could be activated to subsequently yield the desired coupling products in good to excellent yield.

| S-EPMC5671776 | biostudies-literature

Three-Component Aminoarylation of Electron-Rich Alkenes by Merging Photoredox with Nickel Catalysis.

Project description:A three-component 1,2-aminoarylation of vinyl ethers, enamides, ene-carbamates and vinyl thioethers by synergistic photoredox and nickel catalysis is reported. 2,2,2-Trifluoroethoxy carbonyl protected α-amino-oxy acids are used as amidyl radical precursors. anti-Markovnikov addition of the amidyl radical to the alkene and Ni-mediated radical/transition metal cross over lead to the corresponding 1,2-aminoarylation product. The radical cascade, which can be conducted under practical and mild conditions, features high functional group tolerance and broad substrate scope. Stereoselective 1,2-aminoarylation is achieved using a L-(+)-lactic acid derived vinyl ether as the substrate, offering a novel route for the preparation of protected enantiopure α-arylated β-amino alcohols. In addition, 1,2-aminoacylation of vinyl ethers is achieved by using an acyl succinimide as the electrophile for the Ni-mediated radical coupling.

| S-EPMC8252614 | 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