Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Synthesis of Azacarbolines via PhIO₂-Promoted Intramolecular Oxidative Cyclization of α-Indolylhydrazones.

ABSTRACT: An unprecedented synthesis of polysubstituted indole-fused pyridazines (azacarbolines) from α-indolylhydrazones under oxidative conditions using a combination of iodylbenzene (PhIO₂) and trifluoroacetic acid (TFA) has been developed. This transformation is conducted without the need for transition metals, harsh conditions, or an inert atmosphere.

SUBMITTER: Corrieri M

PROVIDER: S-EPMC8689645 | biostudies-literature | 2021 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Synthesis of Azacarbolines via PhIO2-Promoted Intramolecular Oxidative Cyclization of α-Indolylhydrazones.

Corrieri Matteo M De Crescentini Lucia L Mantellini Fabio F Mari Giacomo G Santeusanio Stefania S Favi Gianfranco G

The Journal of organic chemistry 20211206 24

An unprecedented synthesis of polysubstituted indole-fused pyridazines (azacarbolines) from α-indolylhydrazones under oxidative conditions using a combination of iodylbenzene (PhIO2) and trifluoroacetic acid (TFA) has been developed. This transformation is conducted without the need for transition metals, harsh conditions, or an inert atmosphere. ...[more]

PMID: 34871002

Similar Datasets

Enantioselective Synthesis of α,α-Disubstituted Lactones via a Chiral Bronsted Acid Catalyzed Intramolecular Cyclization.

Project description: Not available

| S-EPMC5198840 | biostudies-literature

Synthesis of Oxazinanones: Intramolecular Cyclization of Amino Acid-Derived Diazoketones via Silica-Supported HClO4 Catalysis.

Project description:A Brønsted acid catalyzed intramolecular cyclization of N-Cbz-protected diazoketones, derived from α-amino acids, is described. The reaction proceeds under metal-free conditions and is promoted by ecofriendly silica-supported HClO4 as the catalyst and methanol as the solvent. This transformation enables the short synthesis of various 1,3-oxazinane-2,5-diones under mild reaction conditions and in good yields (up to 90%). The set-up is very simple; by just mixing all reagents together with no work-up necessary before purification, this protocol takes a greener approach.

| S-EPMC6376066 | biostudies-literature

Total Synthesis of Potent Antitumor Macrolide, (-)-Zampanolide: An Oxidative Intramolecular Cyclization-Based Strategy.

Project description:A detailed account of the enantioselective total synthesis of (-)-zampanolide, a macrolide marine natural product with high anti-cancer activity is described. For synthesis of the 4-methylene tetrahydropyran unit of (-)-zampanolide, initially, we relied upon an oxidative C-H activation of an alkenyl ether and intramolecular cyclization to provide the substituted tetrahydropyran ring. However, this strategy was unsuccessful. Subsequently, we found that a cinnamyl ether is critical for the successful oxidative intramolecular cyclization reaction. The synthesis also features a cross metathesis reaction to construct a tri-substituted olefin, a ring-closing metathesis to form a highly functionalized macrolactone and a chiral phosphoric acid promoted N-acyl aminal formation to furnish (-)-zampanolide stereoselectively and in good yield. The synthetic (-)-zampanolide had effects on cultured cells and on tubulin assembly consistent with properties reported for the natural product.

| S-EPMC3629982 | biostudies-literature

Synthesis of Indolyl Phenyl Diketones through Visible-Light-Promoted Ni-Catalyzed Intramolecular Cyclization/Oxidation Sequence of Ynones.

Project description:The combination of visible light catalysis and Ni catalysis has enabled the synthesis of indolyl phenyl diketones through the cyclization/oxidation process of ynones. This reaction proceeded under mild and base-free conditions and showed a broad scope and feasibility for gram-scale synthesis. Several natural products and biologically interesting molecules could be readily postfunctionalized by this method.

| S-EPMC10995934 | biostudies-literature

Synthesis of highly substituted fluorenones via metal-free TBHP-promoted oxidative cyclization of 2-(aminomethyl)biphenyls. Application to the total synthesis of nobilone.

Project description:Highly substituted fluorenones are readily prepared in mostly fair to good yields via metal- and additive-free TBHP-promoted cross-dehydrogenative coupling (CDC) of readily accessible N-methyl-2-(aminomethyl)biphenyls and 2-(aminomethyl)biphenyls. This methodology is compatible with numerous functional groups (methoxy, cyano, nitro, chloro, and SEM and TBS-protective groups for phenols) and was further utilized in the first total synthesis of the natural product nobilone.

| S-EPMC8576822 | biostudies-literature

Diastereoselective pyrrolidine synthesis via copper promoted intramolecular aminooxygenation of alkenes: formal synthesis of (+)-monomorine.

Project description:The diastereoselectivity of the copper-promoted intramolecular aminooxygenation of various alkene substrates was investigated. Alpha-substituted 4-pentenyl sulfonamides favor the formation of 2,5-cis-pyrrolidines (dr >20:1) giving excellent yields which range from 76-97% while gamma-substituted substrates favor the 2,3-trans pyrrolidine adducts with moderate selectivity (ca. 3:1). A substrate whose N-substituent was directly tethered to the alpha-carbon exclusively yielded the 2,5-trans pyrrolidine. The synthetic utility of the method was demonstrated by a short and efficient formal synthesis of (+)-monomorine.

| S-EPMC2714983 | biostudies-literature

A Facile Synthesis of 2-Oxazolines via Dehydrative Cyclization Promoted by Triflic Acid.

Project description:2-oxazolines are common moieties in numerous natural products, pharmaceuticals, and functional copolymers. Current methods for synthesizing 2-oxazolines mainly rely on stoichiometric dehydration agents or catalytic dehydration promoted by specific catalysts. These conditions either generate stoichiometric amounts of waste or require forcing azeotropic reflux conditions. As such, a practical and robust method that promotes dehydrative cyclization while generating no byproducts would be attractive to oxazoline production. Herein, we report a triflic acid (TfOH)-promoted dehydrative cyclization of N-(2-hydroxyethyl)amides for synthesizing 2-oxazolines. This reaction tolerates various functional groups and generates water as the only byproduct. This method affords oxazoline with inversion of α-hydroxyl stereochemistry, suggesting that alcohol is activated as a leaving group under these conditions. Furthermore, the one-pot synthesis protocol of 2-oxazolines directly from carboxylic acids and amino alcohols is also provided.

| S-EPMC9781752 | biostudies-literature

Enantioselective Total Synthesis of Cannogenol-3-O-α-l-rhamnoside via Sequential Cu(II)-Catalyzed Michael Addition/Intramolecular Aldol Cyclization Reactions.

Project description:A concise and scalable enantioselective total synthesis of the natural cardenolides cannogenol and cannogenol-3-O-α-l-rhamnoside has been achieved in 18 linear steps. The synthesis features a Cu(II)-catalyzed enantioselective and diastereoselective Michael reaction/tandem aldol cyclization and a one-pot reduction/transposition, which resulted in a rapid (6 linear steps) assembly of a functionalized intermediate containing C19 oxygenation that could be elaborated to cardenolide cannogenol. In addition, a strategy for achieving regio- and stereoselective glycosylation at the C3 position of synthetic cannogenol was developed and applied to the preparation of cannogenol-3-O-α-l-rhamnoside.

| S-EPMC5768146 | biostudies-literature

Enantioselective total synthesis of (-)-nardoaristolone B via a gold(I)-catalyzed oxidative cyclization.

Project description:The first enantioselective total synthesis of (-)-nardoaristolone B is accomplished by the implementation of an enantio- and diastereoselective copper(I)-catalyzed conjugate addition/enolate trapping sequence and a gold(I)-catalyzed oxidative cyclization (intermolecular oxidant), employed for the first time in total synthesis.

| S-EPMC4322447 | biostudies-other

K2CO3-Promoted oxy-Michael Addition/Cyclization of α,β-Unsaturated Carbonyl Compounds with Naphthols: Synthesis of Naphthopyrans.

Project description:A potassium carbonate promoted tandem oxy-Michael addition/cyclization of α,β-unsaturated carbonyl compounds with naphthol derivatives for the synthesis of 2-substituted naphthopyrans was developed. Using the readily available, inexpensive potassium carbonate as the promoter, a range of different substituted naphthopyrans were prepared.

| S-EPMC10385152 | biostudies-literature