Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Three-component coupling sequence for the regiospecific synthesis of substituted pyridines.

ABSTRACT: A de novo synthesis of substituted pyridines is described that proceeds through nucleophilic addition of a dithiane anion to an ?,?-unsaturated carbonyl followed by metallacycle-mediated union of the resulting allylic alcohol with preformed trimethylsilane-imines (generated in situ by the low-temperature reaction of lithium hexamethyldisilazide with an aldehyde) and Ag(I)- or Hg(II)-mediated ring closure. The process is useful for the convergent assembly of di- through penta-substituted pyridines with complete regiochemical control.

SUBMITTER: Chen MZ

PROVIDER: S-EPMC3262091 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Three-component coupling sequence for the regiospecific synthesis of substituted pyridines.

Chen Ming Z MZ Micalizio Glenn C GC

Journal of the American Chemical Society 20111214 2

A de novo synthesis of substituted pyridines is described that proceeds through nucleophilic addition of a dithiane anion to an α,β-unsaturated carbonyl followed by metallacycle-mediated union of the resulting allylic alcohol with preformed trimethylsilane-imines (generated in situ by the low-temperature reaction of lithium hexamethyldisilazide with an aldehyde) and Ag(I)- or Hg(II)-mediated ring closure. The process is useful for the convergent assembly of di- through penta-substituted pyridine ...[more]

PMID: 22103772

Similar Datasets

A simple, modular synthesis of substituted pyridines.

Project description:A simple, modular method to prepare highly substituted pyridines is disclosed. The method employs a cascade reaction comprising (1) a novel N-iminative, Cu-catalyzed cross-coupling of alkenylboronic acids at the N-O bond of alpha,beta-unsaturated ketoxime O-pentafluorobenzoates, (2) electrocyclization of the resulting 3-azatriene, and (3) air oxidation affording highly substituted pyridines in moderate to excellent isolated yields (43-91%). Starting materials are readily available, and functional group tolerance is very good.

| S-EPMC2664531 | biostudies-literature

Substituted Dihydropyridine Synthesis by Dearomatization of Pyridines.

Project description:Dearomatization is an effective method to transform readily available N-heterocycles into partially saturated motifs. Manipulation of dihydro-derivatives holds great potential and provides access to a variety of semi-saturated N-heterocyclic building blocks. However, current strategies are limited in scope and the use of sensitive reagents restricts the applicability in synthetic laboratories. Herein, we report the synthesis of a broad variety of N-substituted 1,4- and 1,2-dihydropyridines by very mild and selective reduction with amine borane for the first time.

| S-EPMC8252501 | biostudies-literature

One-pot synthesis of tetracyclic fused imidazo[1,2-a]pyridines via a three-component reaction.

Project description:A novel three-component reaction has been developed to assemble biologically and pharmaceutically important tetracyclic fused imidazo[1,2-a]pyridines in a one-pot fashion utilizing readily available 2-aminopyridines, isatins and isocyanides. The three-component coupling proceeds through the Groebke-Blackburn-Bienaymé reaction followed by a retro-aza-ene reaction and subsequent nucleophilic reaction of the in-situ generated imidazo[1,2-a]pyridines bearing an isocyanate functional group.

| S-EPMC4979633 | biostudies-literature

Synthesis of highly substituted benzene ring systems through three-component coupling of enyne imines, Fischer carbene complexes, and electron-deficient alkynes.

Project description:Three-component coupling of Fischer carbene complexes, enyne aldehyde hydrazones, and electron-deficient alkynes leads to simple benzoate derivatives in a process involving the formation of an N-aminopyrrole derivative, Diels-Alder reaction, and nitrene extrusion. The products are readily converted into isoquinolones through reaction with primary amines. The reaction proceeds best with highly substituted and electron-rich pyrroles even though these are the sterically least favorable substrates, and this reactivity trend is supported by a computational study.

| S-EPMC5619673 | biostudies-literature

Preparation of 1,2-substituted benzimidazoles <i>via</i> a copper-catalyzed three component coupling reaction.

Project description:1,2-Substituted benzimidazoles were prepared by simply stirring a mixture of copper catalysts, N-substituted o-phenylenediamines, sulfonyl azides and terminal alkynes. Particularly, the intermediate N-sulfonylketenimine occurred with two nucleophilic addition and the sulfonyl group was eliminated via cyclization. In a way, sulfonyl azides and copper catalysts activated the terminal alkynes to synthesize benzimidazoles.

| S-EPMC8695204 | biostudies-literature

A Merged Aldol Condensation, Alkene Isomerization, Cycloaddition/Cycloreversion Sequence Employing Oxazinone Intermediates for the Synthesis of Substituted Pyridines.

Project description:A domino reaction sequence has been evaluated that begins with union of novel dihydrooxazinone precursors with 2-alkynyl-substituted benzaldehyde components through aldol condensation. Ensuing operations, including alkene isomerization, Diels-Alder, and retrograde Diels-Alder with loss of CO2 occurs in the same reaction vessel to provide polysubstituted tricyclic pyridine products.

| S-EPMC5791744 | biostudies-literature

Hydroxy-Substituted Azacalix[4]Pyridines: Synthesis, Structure, and Construction of Functional Architectures.

Project description:A number of hydroxyl-substituted azacalix[4]pyridines were synthesized using Pd-catalyzed macrocyclic "2+2" and "3+1" coupling methods and the protection-deprotection strategy of hydroxyl group. While the conformation of the these hydroxyl-substituted azacalix[4]pyridines is fluxional in solution, in the solid state, they adopted shape-persistent 1,3-alternate conformations. Besides, X-ray analysis revealed that the existence of hydroxy groups on the para-position of pyridine facilitated the formation of solvent-bridged intermolecular hydrogen bonding for mono-hydroxyl-substituted while partial tautomerization for four-hydroxyl-substituted macrocycles, respectively. Taking the hydroxyl-substituted azacalix[4]pyridines as molecular platforms, multi-macrocycle-containing architectures and functional building blocks were constructed. The self-assembly behavior of the resulting building blocks was investigated in crystalline state.

| S-EPMC6707087 | biostudies-literature

Three-component synthesis of C2F5-substituted pyrazoles from C2F5CH2NH2·HCl, NaNO2 and electron-deficient alkynes.

Project description:A one-pot reaction between C2F5CH2NH2·HCl, NaNO2 and electron-deficient alkynes gives C2F5-substituted pyrazoles in excellent yields. The transformation smoothly proceeds in dichloromethane/water, tolerates the presence of air, and requires no purification of products by column chromatography. Mechanistically, C2F5CH2NH2·HCl and NaNO2 react first in water to generate C2F5CHN2, that participates in a [3 + 2] cycloaddition with electron-deficient alkynes in dichloromethane.

| S-EPMC4311722 | biostudies-literature

Three-component coupling approach for the synthesis of diverse heterocycles utilizing reactive nitrilium trapping.

Project description:The formation of an unexpected heterocyclic scaffold, a benzoxazole, in a three-component reaction between a ketone, isocyanide, and 2-aminophenol was encountered. This reaction involved a benzo[b][1,4]oxazine intermediate resulting from intramolecular attack of the aminophenol hydroxyl group on the nitrilium ion. Unlike previous literature examples, the trapped nitrilium benzo[b][1,4]oxazine could readily be subjected to ring opening with bis-nucleophiles. The reaction scope includes simple linear as well as complex cyclic ketones and substituted 2-aminophenols. A representative benzoxazole product could be further diversified to yield drug-like compounds.

| S-EPMC3969103 | biostudies-literature

Three-component coupling approach to trachyspic acid.

Project description:Three-component coupling of the lithium enolate of t-BuOAc, silyl glyoxylate, and an α,β-unsaturated ketone enables the rapid construction of the trachyspic acid carbon skeleton. A 3,4-disubstituted isoxazole is utilized to mask the C7/C9 dicarbonyl. New enolsilane/nitrile-oxide cycloadditions enable the preparation of various 3,4-disubstituted isoxazoles that are challenging to access by other means.

| S-EPMC3184321 | 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