Browse
Submit Data
Databases
API
Help

Dataset Information

9 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Asymmetric, stereodivergent synthesis of (-)-clusianone utilizing a biomimetic cationic cyclization.

ABSTRACT: We report a stereodivergent, asymmetric total synthesis of (-)-clusianone in six steps from commercial materials. We implement a challenging cationic cyclization forging a bond between two sterically encumbered quaternary carbon atoms. Mechanistic studies point to the unique ability of formic acid to mediate the cyclization forming the clusianone framework.

SUBMITTER: Boyce JH

PROVIDER: S-EPMC4182949 | biostudies-other | 2014 Jul

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Publications

Asymmetric, stereodivergent synthesis of (-)-clusianone utilizing a biomimetic cationic cyclization.

Boyce Jonathan H JH Porco John A JA

Angewandte Chemie (International ed. in English) 20140610 30

We report a stereodivergent, asymmetric total synthesis of (-)-clusianone in six steps from commercial materials. We implement a challenging cationic cyclization forging a bond between two sterically encumbered quaternary carbon atoms. Mechanistic studies point to the unique ability of formic acid to mediate the cyclization forming the clusianone framework. ...[more]

PMID: 24916169

Similar Datasets

Biomimetic Total Synthesis of (±)-Griffipavixanthone via a Cationic Cycloaddition-Cyclization Cascade.

Project description:We report the concise, biomimetic total synthesis of the dimeric, Diels-Alder natural product griffipavixanthone from a readily accessible prenylated xanthone monomer. The key step utilizes a novel intermolecular [4+2] cycloaddition-cyclization cascade between a vinyl p-quinone methide and an in situ generated isomeric diene promoted by either Lewis or Brønsted acids. Experimental and computational studies of the reaction pathway suggest that a stepwise, cationic Diels-Alder cycloaddition is operative.

| S-EPMC5718057 | biostudies-literature

An organocatalytic asymmetric Nazarov cyclization.

Project description:An organocatalytic asymmetric Nazarov cyclization of diketoesters that proceeds by means of a dual activation mechanism has been developed. Screening of a number of catalysts led to a new thiourea that incorporates a primary amino group. The method gives rise to cyclic products with two adjacent quaternary asymmetric carbon atoms, one of which is an all-carbon stereocenter, with complete or nearly complete diastereoselectivity and in high or very high enantiomeric excess. A brief and very convenient synthesis of the acyclic diketoester starting materials through nucleophilic addition to a ketene is also described.

| S-EPMC2903437 | biostudies-other

Enantioselective Synthesis of Fluoro-Dihydroquinazolones and -Benzooxazinones by Fluorination-Initiated Asymmetric Cyclization Reactions.

Project description:Stereoselective synthesis of two fluorine-bearing drug-like scaffolds, dihydroquinazolone and benzooxazinone, has been accomplished through asymmetric fluorocyclization reactions initiated by the fluorination process. The reaction employs double axially chiral anionic phase-transfer catalysts to achieve high diastereo- and enantioselectivities, and a wide range of fluorine-containing dihydroquinazolones were obtained (>20:1 dr, up to 98% ee).

| S-EPMC5154691 | biostudies-literature

A general route toward the synthesis of the cladiellin skeleton utilizing a SmI2-mediated cyclization.

Project description:An efficient synthesis of the cladiellin skeleton is reported utilizing methods that were previously developed in this laboratory. The approach is based on a SmI(2)-mediated cyclization reaction for the construction of the oxacyclononane unit. A [4 + 3] annulation strategy was used to create the octahydroisobenzofuran moiety. This route provides the cladiellin skeleton in only 14 steps without the use of protecting groups. The present approach also enabled the synthesis of the 3,7-diastereomer of the natural product polyanthellin A.

| S-EPMC2505338 | biostudies-literature

A stereoselective synthesis of (-)-viridiofungin A utilizing a TiCl(4)-promoted asymmetric multicomponent reaction.

Project description:A stereoselective synthesis of (-)-viridiofungin A is described. The convergent synthesis utilized a unique highly diastereoselective multicomponent reaction between optically active phenyldihydrofuran and an ?-ketoester to provide two chiral centers including a quarternary carbon center in a single step. Other key steps include an acyloxycarbonium ion-mediated tetrahydrofuran ring-opening reaction and a Julia-Kocienski olefination.

| S-EPMC3262899 | biostudies-literature

Meroterpenoid Synthesis via Sequential Polyketide Aromatization and Radical Anion Cascade Triene Cyclization: Biomimetic Total Syntheses of Austalide Natural Products.

Project description:The first total synthesis of five austalide natural products, (±)-17 S-dihydroaustalide K, (±)-austalide K, (±)-13-deacetoxyaustalide I, (±)-austalide P, and (±)-13-deoxyaustalide Q acid, was accomplished via a series of biomimetic transformations. Key steps involved polyketide aromatization of a trans, trans-farnesol-derived ?,?-diketodioxinone into the corresponding ?-resorcylate, followed by titanium(III)-mediated reductive radical cyclization of an epoxide to furnish the drimene core. Subsequent phenylselenonium ion induced diastereoselective cyclization of the drimene completed the essential carbon framework of the austalides to access (±)-17 S-dihydroaustalide K, (±)-austalide K, and (±)-13-deacetoxyaustalide I via sequential oxidations. Furthermore, (±)-13-deacetoxyaustalide I could serve as a common intermediate to be derivatized into other related natural products, (±)-austalide P and (±)-13-deoxyaustalide Q acid, by functionalizing the cyclic lactone moiety.

| S-EPMC7007238 | biostudies-literature

Asymmetric synthesis of tetrahydropyridines via an organocatalytic one-pot multicomponent Michael/aza-Henry/cyclization triple domino reaction.

Project description:A low loading of a quinine-derived squaramide efficiently catalyzes the triple-domino Michael/aza-Henry/cyclization reaction between 1,3-dicarbonyl compounds, ?-nitroolefins, and aldimines to provide tetrahydropyridines bearing three contiguous stereogenic centers in good yields, excellent enantiomeric excesses, and up to high diastereomeric ratios.

| S-EPMC4611353 | biostudies-literature

Synthesis of bridged tricyclo[5.2.1.0<sup>1,5</sup>]decanes via nickel-catalyzed asymmetric domino cyclization of enynones.

Project description:The restricted availability, expense and toxicity of precious metal catalysts such as rhodium and palladium challenge the sustainability of synthetic chemistry. As such, nickel catalysts have garnered increasing attention as replacements for enyne cyclization reactions. On the other hand, bridged tricyclo[5.2.1.01,5]decanes are found as core structures in many biologically active natural products; however, the synthesis of such frameworks with high functionalities from readily available precursors remains a significant challenge. Herein, we report a nickel-catalyzed asymmetric domino cyclization reaction of enynones, providing rapid and modular synthesis of bridged tricyclo[5.2.1.01,5]decane skeletons with three quaternary stereocenters in good yields and remarkable high levels of regio- and enantioselectivities (92-99% ee).

| S-EPMC7171102 | biostudies-literature

Asymmetric Dearomatization/Cyclization Enables Access to Polycyclic Chemotypes.

Project description:Enantioenriched, polycyclic compounds were obtained from a simple acylphloroglucinol scaffold. Highly enantioselective dearomatization was accomplished using a Trost ligand-palladium(0) complex. A computational DFT model was developed to rationalize observed enantioselectivities and revealed a key reactant-ligand hydrogen bonding interaction. Dearomatized products were used in visible light-mediated photocycloadditions and oxidative free radical cyclizations to obtain novel polycyclic chemotypes including tricyclo[4.3.1.01,4]decan-10-ones, bicyclo[3.2.1]octan-8-ones and highly-substituted cycloheptanones.

| S-EPMC5222469 | biostudies-literature

Enantioselective Synthesis of Spirooxindole Enols: Regioselective and Asymmetric [3+2] Cyclization of 3-Isothiocyanato Oxindoles with Dibenzylidene Ketones.

Project description:A novel cinchona-alkaloid-derived organocatalyst has been developed to catalyze the asymmetric regioselective [3+2] cycloaddition of 3-isothiocyanato oxindoles with dibenzylidene ketones. A series of spirooxindole enols could be obtained in high yields with good-to-excellent diastereo- and enantioselectivities.

| S-EPMC4981050 | 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