Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Synthesis of Various 2-Aminobenzoxazoles: The Study of Cyclization and Smiles Rearrangement.

ABSTRACT: This study reports two synthetic approaches leading to 2-aminobenzoxazoles and their N-substituted analogues. Our first synthetic strategy involves a reaction between various o-aminophenols and N-cyano-N-phenyl-p-toluenesulfonamide as a nonhazardous electrophilic cyanating agent in the presence of Lewis acid. The second synthetic approach uses the Smiles rearrangement upon activation of benzoxazole-2-thiol with chloroacetyl chloride. Both developed synthetic protocols are widely applicable, afford the desired aminobenzoxazoles in good to excellent yields, and use nontoxic and inexpensive starting material.

SUBMITTER: Slachtova V

PROVIDER: S-EPMC6868899 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Synthesis of Various 2-Aminobenzoxazoles: The Study of Cyclization and Smiles Rearrangement.

Šlachtová Veronika V Chasák Jan J Brulíková Lucie L

ACS omega 20191105 21

This study reports two synthetic approaches leading to 2-aminobenzoxazoles and their N-substituted analogues. Our first synthetic strategy involves a reaction between various o-aminophenols and N-cyano-N-phenyl-p-toluenesulfonamide as a nonhazardous electrophilic cyanating agent in the presence of Lewis acid. The second synthetic approach uses the Smiles rearrangement upon activation of benzoxazole-2-thiol with chloroacetyl chloride. Both developed synthetic pr ...[more]

PMID: 31763555

Similar Datasets

Synthesis of 7-Aminocoumarins from 7-Hydroxycoumarins via Amide Smiles Rearrangement.

Project description:N-Substituted 7-aminocoumarins can be synthesized from readily available 7-hydroxycoumarins via alkylation with α-bromoacetamides and subsequent tandem O → N Smiles rearrangement-amide hydrolysis. The key rearrangement sequence proceeds under mild conditions to provide convenient access to various N-alkyl and N-aryl products in moderate to high yields. The process is operationally simple, inexpensive, transition-metal-free, and can be telescoped into a one-pot process.

| S-EPMC9535735 | biostudies-literature

Metal Free Bi(hetero)aryl Synthesis: A Benzyne Truce-Smiles Rearrangement.

Project description:A new benzyne transformation is described that affords versatile biaryl structures without recourse to transition-metal catalysis or stoichiometric amounts of organometallic building blocks. Aryl sulfonamides add to benzyne upon fluoride activation, and then undergo an aryl Truce-Smiles rearrangement to afford biaryls with sulfur dioxide extrusion. The reaction proceeds under simple reaction conditions and has excellent scope for the synthesis of sterically hindered atropisomeric biaryl amines.

| S-EPMC4819888 | biostudies-other

Production of Stealthin C Involves an S-N-Type Smiles Rearrangement.

Project description:The kinamycin family of aromatic polyketide natural products contains an atypical angucycline ring system substituted with a diazo group. The enzymatic chemistry involved in constructing both of these structural features has been largely unexplored. Here we report the in vivo and in vitro production of seongomycin, a shunt product from this pathway, and stealthin C, a proposed biosynthetic precursor to the kinamycins. We show that a single enzyme, the flavin-dependent monooxygenase AlpJ, can generate these metabolites from N-acetyl-l-cysteine and l-cysteine, respectively, and that the synthesis of stealthin C likely proceeds via a nonenzymatic S-N-type Smiles rearrangement. This unexpected route to stealthin C reveals a distinct approach to install aromatic amino groups in metabolites and raises questions about the intermediacy of this species in kinamycin production.

| S-EPMC5498114 | biostudies-literature

Si-based benzylic 1,4-rearrangement/cyclization reaction.

Project description:The trans-selective hydrosilylation of ynones (1) yields beta-silylated enones (2) that undergo a benzylic 1,4-rearrangement/cyclization reaction in the presence of base, yielding 2,5-dihydro-1,2-oxasiloles (3).

| S-EPMC2640427 | biostudies-literature

A Visible-Light-Mediated Radical Smiles Rearrangement and its Application to the Synthesis of a Difluoro-Substituted Spirocyclic ORL-1 Antagonist.

Project description:A visible-light-mediated radical Smiles rearrangement has been developed to address the challenging synthesis of the gem-difluoro group present in an opioid receptor-like?1 (ORL-1) antagonist that is currently in development for the treatment of depression and/or obesity. This method enables the direct and efficient introduction of the difluoroethanol motif into a range of aryl and heteroaryl systems, representing a new disconnection for the synthesis of this versatile moiety. When applied to the target compound, the photochemical step could be conducted on 15?g scale using industrially relevant [Ru(bpy)3Cl2] catalyst loadings of 0.01?mol?%. This transformation is part of an overall five-step route to the antagonist that compares favorably to the current synthetic sequence and demonstrates, in this specific case, a clear strategic benefit of photocatalysis.

| S-EPMC4725294 | biostudies-literature

Facile Smiles-type rearrangement in radical cations of N-acyl arylsulfonamides and analogs.

Project description:N-Alkylation of sulfonylbenzamides was reported recently to cause a dramatic and surprising change in electron ionization mass spectrometry (EIMS), leading to a closed-shell base peak. Only an incomplete, speculative mechanism was available at that time. The fragmentation mechanism is determined in the present work and set in the context of related compounds.Candidate reaction mechanisms were evaluated theoretically using modest density-functional calculations. The fragmentation mechanism with the lowest barriers was identified and one of its implications tested successfully by experimental (18) O-isotopic substitution.The amide oxygen atom attacks the arylsulfonyl group at the ipso position (Smiles-type rearrangement), displacing a molecule of SO2 . The resulting carboximidate radical cation has a weak C-O bond that breaks easily. The incipient aryloxyl radical abstracts a proton from the amide nitrogen to form the dominant product ion, but if the molecule is N-alkylated this cannot occur. Instead, the neutral aryloxyl radical is lost and a closed-shell, N-alkyl nitrilium ion is the major product.The Smiles-type ion fragmentation mechanism is facile for the title compounds, despite the necessity for carbonyl oxygen to serve as a nucleophile. This rearrangement probably occurs in many of the mass spectra reported for structurally similar compounds, in which the nucleophile may be a thione, arylthio, imine, methylene, or methine moiety.

| S-EPMC5096379 | biostudies-literature

Triarylmethanes and their Medium-Ring Analogues by Unactivated Truce-Smiles Rearrangement of Benzanilides.

Project description:Intramolecular nucleophilic aromatic substitution (Truce-Smiles rearrangement) of the anions of 2-benzyl benzanilides leads to triarylmethanes in an operationally simple manner. The reaction succeeds even without electronic activation of the ring that plays the role of electrophile in the SN Ar reaction, being accelerated instead by the preferred conformation imposed by the tertiary amide tether. The amide substituent of the product may be removed or transformed into alternative functional groups. A ring-expanding variant (n to n+4) of the reaction provided a route to doubly benzo-fused medium ring lactams of 10 or 11 members. Hammett analysis returned a ρ value consistent with the operation of a partially concerted reaction mechanism.

| S-EPMC8252078 | biostudies-literature

Electrophile-integrating Smiles rearrangement provides previously inaccessible C4'-O-alkyl heptamethine cyanine fluorophores.

Project description:New synthetic methods to rapidly access useful fluorophores are needed to advance modern molecular imaging techniques. A new variant of the classical Smiles rearrangement is reported that enables the efficient synthesis of previously inaccessible C4'-O-alkyl heptamethine cyanines. The key reaction involves N- to O-transposition with selective electrophile incorporation on nitrogen. A representative fluorophore exhibits excellent resistance to thiol nucleophiles, undergoes productive bioconjugation, and can be used in near-IR fluorescence imaging applications.

| S-EPMC4301176 | biostudies-other

IBD-mediated oxidative cyclization of pyrimidinylhydrazones and concurrent Dimroth rearrangement: Synthesis of [1,2,4]triazolo[1,5-c]pyrimidine derivatives.

Project description:Oxidative cyclization of 6-chloro-4-pyrimidinylhydrazones 4 with iodobenzene diacetate (IBD) in dichloromethane gives rise to [1,2,4]triazolo[4,3-c]pyrimidine derivatives 5a-o. These incipient products undergo feasible Dimroth rearrangement to furnish the isolated [1,2,4]triazolo[1,5-c]pyrimidines 6a-o in moderate to high yields.

| S-EPMC3869367 | biostudies-literature

Efficient Nazarov cyclization/Wagner-Meerwein rearrangement terminated by a Cu(II)-promoted oxidation: synthesis of 4-alkylidene cyclopentenones.

Project description:The discovery and elucidation of a new Nazarov cyclization/Wagner-Meerwein rearrangement/oxidation sequence is described that constitutes an efficient strategy for the synthesis of 4-alkylidene cyclopentenones. DFT computations and EPR experiments were conducted to gain further mechanistic insight into the reaction pathways.

| S-EPMC3887475 | 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