Browse
Submit Data
Databases
API
Help

Dataset Information

0 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

Biomimetic Cationic Cyclopropanation Enables an Efficient Chemoenzymatic Synthesis of 6,8-Cycloeudesmanes.

Project description:Cationic cyclopropanation involves the γ-elimination at carbocations to form a new σ-C-C bond through proton loss. While exceedingly rare in bulk solution, it is recognized as one of the main biosynthetic cyclopropanation pathways. Despite the rich history of bioinspired synthetic chemistry, cationic cyclopropanation has not been appropriated for the synthetic toolbox, likely due to the preference of carbocations to undergo competing E1 β-elimination pathways. Here, we present an in-depth synthetic and computational study of cationic cyclopropanation, focusing on the 6,8-cycloeudesmanes as a platform for this investigation. We were able to apply biomimetic cationic cyclopropanation to the synthesis of several 6,8-cycloeudesmanes and non-natural analogues─in doing so, we showcase the power of this transformation in the preparation of complex cyclopropanes.

| S-EPMC10021018 | 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

Asymmetric amine-intercepted Nazarov cyclization.

Project description: Not available

| S-EPMC2518941 | 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

Rational enzyme design for enabling biocatalytic Baldwin cyclization and asymmetric synthesis of chiral heterocycles.

Project description:Chiral heterocyclic compounds are needed for important medicinal applications. We report an in silico strategy for the biocatalytic synthesis of chiral N- and O-heterocycles via Baldwin cyclization modes of hydroxy- and amino-substituted epoxides and oxetanes using the limonene epoxide hydrolase from Rhodococcus erythropolis. This enzyme normally catalyzes hydrolysis with formation of vicinal diols. Firstly, the required shutdown of the undesired natural water-mediated ring-opening is achieved by rational mutagenesis of the active site. In silico enzyme design is then continued with generation of the improved mutants. These variants prove to be versatile catalysts for preparing chiral N- and O-heterocycles with up to 99% conversion, and enantiomeric ratios up to 99:1. Crystal structural data and computational modeling reveal that Baldwin-type cyclizations, catalyzed by the reprogrammed enzyme, are enabled by reshaping the active-site environment that directs the distal RHN and HO-substituents to be intramolecular nucleophiles.

| S-EPMC9763437 | biostudies-literature

Asymmetric oxidative cation/olefin cyclization of polyenes: evidence for reversible cascade cyclization.

Project description: Not available

| S-EPMC2908993 | 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 α-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

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

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