Browse
Submit Data
Databases
API
Help

Dataset Information

13 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

An intramolecular C-N cross-coupling of ?-enaminones: a simple and efficient way to precursors of some alkaloids of Galipea officinalis.

ABSTRACT: 2-Aroylmethylidene-1,2,3,4-tetrahydroquinolines with the appropriate substituents can be suitable precursors for the synthesis of alkaloids from Galipea officinalis (cuspareine, galipeine, galipinine, angustureine). However, only two, rather low-yielding procedures for their synthesis are described in the literature. We have developed a simple and efficient protocol for an intramolecular, palladium or copper-catalysed amination of both chloro- and bromo-substituted 3-amino-1,5-diphenylpent-2-en-1-ones leading to the above-mentioned tetrahydroquinoline moiety. The methodology is superior to the methods published to date.

SUBMITTER: Dousova H

PROVIDER: S-EPMC4464440 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

An intramolecular C-N cross-coupling of β-enaminones: a simple and efficient way to precursors of some alkaloids of Galipea officinalis.

Doušová Hana H Horák Radim R Růžičková Zdeňka Z Šimůnek Petr P

Beilstein journal of organic chemistry 20150527

2-Aroylmethylidene-1,2,3,4-tetrahydroquinolines with the appropriate substituents can be suitable precursors for the synthesis of alkaloids from Galipea officinalis (cuspareine, galipeine, galipinine, angustureine). However, only two, rather low-yielding procedures for their synthesis are described in the literature. We have developed a simple and efficient protocol for an intramolecular, palladium or copper-catalysed amination of both chloro- and bromo-substituted 3-amino-1,5-diphenylpent-2-en- ...[more]

PMID: 26124890

Similar Datasets

Direct Hiyama cross-coupling of enaminones with triethoxy(aryl)silanes and dimethylphenylsilanol.

Project description:2,3-Dihydropyridin-4(1H)-ones undergo direct C-H functionalization at C5 in the palladium(II)-catalyzed Hiyama reaction, using triethoxy(aryl)silanes and dimethylphenylsilanol. The reagent CuF(2) has a dual role in the reactions with triethoxy(aryl)silanes. It is a source of fluoride to activate the silane in the Hiyama reaction and also serves as the reoxidant to convert Pd(0) to Pd(II) in the catalytic cycle.

| S-EPMC3226827 | biostudies-literature

Bronsted acid mediated cyclization of enaminones. Rapid and efficient access to the tetracyclic framework of the Strychnos alkaloids.

Project description:The development of an efficient diastereoselective method that permits rapid construction of the tetracyclic core 17 of the Strychnos-Aspidosperma alkaloids is described. Enaminone 16, synthesized in high yield, has been cyclized under the influence of a Brønsted acid to provide the core tetracyclic framework 17 of the Strychnos alkaloids in optically active form or alternatively to the ?-ketoester tetrahydro-?-carboline (THBC) unit 18, by varying the equivalents of acid and the molar concentration. Attempts to utilize 18 to form the C?-C?? bond of the akuammiline related alkaloids represented by strictamine (22), using metal-carbenoid chemistry, are also described.

| S-EPMC3288251 | biostudies-literature

Simple, Efficient Protocols for the Pd-Catalyzed Cross-Coupling Reaction of Aryl Chlorides and Dimethylamine.

Project description:Simple and efficient procedures for the Pd-catalyzed cross-coupling reaction of aryl chlorides and dimethylamine are described. At room temperature with a strong base, t-BuXPhos is employed as the supporting ligand; at 110 °C with a weak base, XPhos is employed as the supporting ligand. In each of these cases, commercially available solutions constitute the source of the dimethylamine, and recently disclosed precatalysts constitute the source of the ligand and Pd. This work further expands the utility of these precatalysts in reactions that benefit from an easily activated source of L(1)Pd(0).

| S-EPMC3148836 | biostudies-literature

Indole Alkaloids from the Leaves of Nauclea officinalis.

Project description:Three new indole alkaloids, named naucleamide G (1), and nauclealomide B and C (5 and 6), were isolated from the n-BuOH-soluble fraction of an EtOH extract of the leaves of Nauclea officinalis, together with three known alkaloids, paratunamide C (2), paratunamide D (3) and paratunamide A (4). The structures with absolute configurations of the new compounds were identified on the basis of 1D and 2D NMR, HRESIMS, acid hydrolysis and quantum chemical circular dichroism (CD) calculation. According to the structures of isolated indole alkaloids, their plausible biosynthetic pathway was deduced.

| S-EPMC6273496 | biostudies-other

Enantioselective carbocycle formation through intramolecular Pd-catalyzed allyl-aryl cross-coupling.

Project description:Aryl electrophiles containing tethered allylboronate units undergo efficient intramolecular coupling in the presence of a chiral palladium catalyst to give enantioenriched carbocyclic products. The reaction is found to be quite general, affording 5, 6, and 7-membered carbocyclic products as single regioisomers and with moderate enantioselectivities. Examination of differential coupling partners points to rapid allyl-equilibration as a key stereodefining feature.

| S-EPMC4156259 | biostudies-literature

Simple and efficient way of speeding up transmission calculations with k-point sampling.

Project description:The transmissions as functions of energy are central for electron or phonon transport in the Landauer transport picture. We suggest a simple and computationally "cheap" post-processing scheme to interpolate transmission functions over k-points to get smooth well-converged average transmission functions. This is relevant for data obtained using typical "expensive" first principles calculations where the leads/electrodes are described by periodic boundary conditions. We show examples of transport in graphene structures where a speed-up of an order of magnitude is easily obtained.

| S-EPMC4578408 | biostudies-literature

Intramolecular arylation of benzimidazoles via Pd(II)/Cu(I) catalyzed cross-dehydrogenative coupling.

Project description:Electron poor benzimidazole substrates were arylated via an intramolecular cross-dehydrogenative coupling (CDC) reaction. These CDC reactions were catalyzed by a Pd(II)/Cu(I) catalyst system, capable of producing moderate yields on a large library of substrates. The substrate scope consisted of tethered arene-benzimidazoles that upon coupling, produced a fused polycyclic motif.

| S-EPMC3993984 | biostudies-literature

Beta-aminoethyltrifluoroborates: efficient aminoethylations via Suzuki-Miyaura cross-coupling.

Project description:A set of phenethylamines has been successfully prepared via Suzuki-Miyaura cross-coupling of diverse potassium beta-aminoethyltrifluoroborates with aryl halides. The potassium beta-aminoethyltrifluoroborates were easily prepared via hydroboration of enamine and enamide precursors. [reaction: see text].

| S-EPMC2593899 | biostudies-literature

Synthesis of alkaloid (-)-205B via stereoselective reductive cross-coupling and intramolecular [3+2] cycloaddition.

Project description:An asymmetric synthesis of alkaloid (-)-205B, a tricyclic member of the architecturally diverse family of natural products isolated from the skin of neotropical poison frogs, is described that proceeds through two recently developed stereoselective synthetic methods: (1) Ti-mediated allylic alcohol-imine reductive cross-coupling and (2) intramolecular [3+2] cycloaddition of a glyoxylate-based homoallylic nitrone. The utility of this latter cycloaddition process for the assembly of the stereochemically dense piperidine core of 205B is noteworthy, as this method enables direct [3+2] cycloaddition of an intermediate homoallylic (E)-nitrone via a pathway that is stereochemically unscathed by competitive [3,3]-sigmatropic rearrangement processes. Overall, the synthesis is asymmetric, concise, and highly stereoselective-features which point to the potential future utility of these chemical methods in natural product synthesis and medicinal chemistry.

| S-EPMC3470905 | biostudies-literature

Efficient palladium-catalyzed cross-coupling of highly acidic substrates, nitroacetates.

Project description:Palladium-catalyzed cross-coupling conditions were developed that efficiently afford 2-aryl-2-nitroacetates from aryl bromides and the very acidic nitroacetates.

| S-EPMC3289998 | 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