Browse
Submit Data
Databases
API
Help

Dataset Information

45 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Regioselective intramolecular dipolar cycloaddition of azides and unsymmetrical alkynes.

ABSTRACT: Enantioenriched allenylsilanes are used in three-component propargylation reactions with aldehydes and silyl ethers to form syn-homopropargylic ethers that contain an imbedded azide. These materials then undergo thermally induced intramolecular 1,3-dipolar cycloaddition reactions, resulting in unique fused ring systems containing 1,2,3-triazoles. The ability to modify all three components of the reaction allows for expedient access to compounds containing significant structural and stereochemical variation.

SUBMITTER: Brawn RA

PROVIDER: S-EPMC3164318 | biostudies-literature | 2010 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Regioselective intramolecular dipolar cycloaddition of azides and unsymmetrical alkynes.

Brawn Ryan A RA Welzel Morgan M Lowe Jason T JT Panek James S JS

Organic letters 20100101 2

Enantioenriched allenylsilanes are used in three-component propargylation reactions with aldehydes and silyl ethers to form syn-homopropargylic ethers that contain an imbedded azide. These materials then undergo thermally induced intramolecular 1,3-dipolar cycloaddition reactions, resulting in unique fused ring systems containing 1,2,3-triazoles. The ability to modify all three components of the reaction allows for expedient access to compounds containing significant structural and stereochemica ...[more]

PMID: 20017521

Similar Datasets

Synthesis of functionalized organotrifluoroborates via the 1,3-dipolar cycloaddition of azides.

Project description:[reaction: see text] We have successfully prepared potassium azidoalkyltrifluoroborates from the corresponding halogen compounds in 94-98% yields through a nucleophilic substitution reaction with NaN(3). In the presence of various alkynes and Cu(I) as a catalyst, these azidotrifluoroborates easily formed 1,4-disubstituted organo-[1,2,3]-triazol-1-yl-trifluoroborates in 85-98% yields. This method was then developed into a facile one-pot synthesis for the preparation of various organo-[1,2,3]-triazol-1-yl-trifluoroborates using haloalkyltrifluoroborates as the starting materials.

| S-EPMC2515368 | biostudies-literature

1,3-Dipolar cycloaddition reactivities of perfluorinated aryl azides with enamines and strained dipolarophiles.

Project description:The reactivities of enamines and predistorted (strained) dipolarophiles toward perfluoroaryl azides (PFAAs) were explored experimentally and computationally. Kinetic analyses indicate that PFAAs undergo (3 + 2) cycloadditions with enamines up to 4 orders of magnitude faster than phenyl azide reacts with these dipolarophiles. DFT calculations were used to identify the origin of this rate acceleration. Orbital interactions between the cycloaddends are larger due to the relatively low-lying LUMO of PFAAs. The triazolines resulting from PFAA-enamine cycloadditions rearrange to amidines at room temperature, while (3 + 2) cycloadditions of enamines and phenyl azide yield stable, isolable triazolines. The 1,3-dipolar cycloadditions of norbornene and DIBAC also show increased reactivity toward PFAAs over phenyl azide but are slower than enamine-azide cycloadditions.

| S-EPMC4351169 | biostudies-literature

Additive-assisted regioselective 1,3-dipolar cycloaddition of azomethine ylides with benzylideneacetone.

Project description:1,3-Dipolar cycloadditions of isatins, benzylamine and benzylideneacetones were studied to prepare a series of novel spiropyrrolidine-oxindoles - 4'-acetyl-3',5'-diarylspiro[indoline-3,2'-pyrrolidin]-2-ones and 3'-acetyl-4',5'-diarylspiro[indoline-3,2'-pyrrolidine]-2-ones in good yields of up to 94% and with good regioselectivities. Regioselectivities are reversible by the addition of water or 4-nitrobenzoic acid, respectively. The substituent effects on the regioselectivity were also investigated.

| S-EPMC3943969 | biostudies-literature

Intramolecular diels-alder/1,3-dipolar cycloaddition cascade of 1,3,4-oxadiazoles.

Project description:Full details of a systematic exploration of the intramolecular [4 + 2]/[3 + 2] cycloaddition cascade of 1,3,4-oxadiazoles are disclosed in which the scope and utility of the reaction are defined.

| S-EPMC2587417 | biostudies-literature

Predictable and regioselective insertion of internal unsymmetrical alkynes in rhodium-catalyzed cycloadditions with alkenyl isocyanates.

Project description:A regioselective, rhodium-catalyzed cycloaddition between a variety of internal, unsymmetrical alkynes is described. We document the impact of both steric and electronic properties of the alkyne on reaction course, efficiency, and enantioselectivity. The substituent that better stabilizes a positive charge or the larger group, all else being equal, inserts distal to the carbonyl moiety in a predictable and controllable fashion. The reaction scope is broad and the enantioselectivities are high, providing an "instruction manual" for substrate choice when utilizing this reaction as a synthetic tool.

| S-EPMC2737069 | biostudies-literature

Synthesis of 1-azaspiro[4.4]nonan-1-oxyls via intramolecular 1,3-dipolar cycloaddition.

Project description:Sterically shielded nitroxides of the pyrrolidine series have shown the highest resistance to reduction. Here we report the synthesis of new pyrrolidine nitroxides from 5,5-dialkyl-1-pyrroline N-oxides via the introduction of a pent-4-enyl group to the nitrone carbon followed by an intramolecular 1,3-dipolar cycloaddition reaction and isoxazolidine ring opening. The kinetics of reduction of the new nitroxides with ascorbate were studied and compared to those of previously published (1S,2R,3'S,4'S,5'S,2?R)-dispiro[(2-hydroxymethyl)cyclopentan-1,2'-(3',4'-di-tert-butoxy)pyrrolidine-5',1?-(2?-hydroxymethyl)cyclopentane]-1'-oxyl (1).

| S-EPMC6720653 | biostudies-literature

An intramolecular relay catalysis strategy for Knoevenagel condensation and 1,3-dipolar cycloaddition domino reactions.

Project description:A relay catalysis strategy was established by using a bifunctional catalyst which was prepared by immobilization of organic chains containing secondary amine and Cu(ii) complex onto silica-coated nano-Fe3O4. The simply prepared nanoparticles acted as efficient, intramolecular relays and magnetically recyclable base-metal bifunctional catalysts for Knoevenagel condensation and 1,3-dipolar cycloaddition domino reactions to prepare 5-substituted 1H-tetrazoles with excellent yields.

| S-EPMC9073340 | biostudies-literature

Introduction of an isoxazoline unit to the β-position of porphyrin via regioselective 1,3-dipolar cycloaddition reaction.

Project description:Isoxazoline-linked porphyrins have been synthesized by a regioselective 1,3-dipolar cycloaddition reaction between vinylporphyrin 2 and nitrile oxides. The steric interaction directed the reaction trajectory, in which only the product with a link between the 5-position of the isoxazoline and the β-position of porphyrin was observed. The isoxazoline-porphyrins 3a,b have been characterized by absorption, emission, 1H NMR and mass spectra. Later, the crystal structure of 3a was obtained and confirmed the basic features of the NMR-derived structure. Furthermore, a pair of enantiomers of 3a presented in the crystal, which formed a dimeric complex through intermolecular coordination between the Zn2+ center and the carbonyl group of the second molecule.

| S-EPMC6604739 | biostudies-literature

A study of the scope and regioselectivity of the ruthenium-catalyzed [3 + 2]-cycloaddition of azides with internal alkynes.

Project description:[3 + 2]-Cycloadditions of alkyl azides with various unsymmetrical internal alkynes in the presence of CpRuCl(PPh3)2 as catalyst in refluxing benzene have been examined, leading to 1,4,5-trisubstituted-1,2,3-triazoles. Whereas alkyl phenyl and dialkyl acetylenes undergo cycloadditions to afford mixtures of regioisomeric 1,2,3-triazoles, acyl-substituted internal alkynes react with complete regioselectivity. In addition, propargyl alcohols and propargyl amines were found to react with azides to afford single regioisomeric products.

| S-EPMC2518321 | biostudies-literature

Facile synthesis of stapled, structurally reinforced peptide helices via a photoinduced intramolecular 1,3-dipolar cycloaddition reaction.

Project description:We report the first use of a photoinduced 1,3-dipolar cycloaddition reaction in "stapling" peptide sidechains to reinforce a model peptide helical structure with moderate to excellent yields; the resulting pyrazoline "staplers" exhibit unique fluorescence useful in a cell permeability study.

| S-EPMC2765658 | 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