Browse
Submit Data
Databases
API
Help

Dataset Information

24 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Rhenium(VII) catalysis of Prins cyclization reactions.

ABSTRACT: The rhenium(VII) complex O3ReOSiPh3 is a particularly effective catalyst for Prins cyclizations using aromatic and alpha,beta-unsaturated aldehydes. The reaction conditions are mild, and the highly substituted 4-hydroxytetrahydropyran products are formed stereoselectively. Rhenium(VII) complexes appear to spontaneously form esters with alcohols and to directly activate electron-rich alcohols for solvolysis. Re2O7 and perrhenic acid are equally effective in catalyzing these cyclizations.

SUBMITTER: Tadpetch K

PROVIDER: S-EPMC2665917 | biostudies-literature | 2008 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Rhenium(VII) catalysis of Prins cyclization reactions.

Tadpetch Kwanruthai K Rychnovsky Scott D SD

Organic letters 20080925 21

The rhenium(VII) complex O3ReOSiPh3 is a particularly effective catalyst for Prins cyclizations using aromatic and alpha,beta-unsaturated aldehydes. The reaction conditions are mild, and the highly substituted 4-hydroxytetrahydropyran products are formed stereoselectively. Rhenium(VII) complexes appear to spontaneously form esters with alcohols and to directly activate electron-rich alcohols for solvolysis. Re2O7 and perrhenic acid are equally effective in catalyzing these cyclizations. ...[more]

PMID: 18816133

Similar Datasets

Racemization in Prins cyclization reactions.

Project description:Isotopic labeling experiments were performed to elucidate a new mechanism for racemization in Prins cyclization reactions. The loss in optical activity for these reactions was shown to occur by 2-oxonia-Cope rearrangements by way of a (Z)-oxocarbenium ion intermediate. Reaction conditions such as solvent, temperature, and the nucleophile employed played a critical role in whether an erosion in enantiomeric excess was observed. Additionally, certain structural features of Prins cyclization precursors were also shown to be important for preserving optical purity in these reactions.

| S-EPMC2483253 | biostudies-literature

Cooperative Hydrogen-Bond-Donor Catalysis with Hydrogen Chloride Enables Highly Enantioselective Prins Cyclization Reactions.

Project description:Cooperative asymmetric catalysis with hydrogen chloride (HCl) and chiral dual-hydrogen-bond donors (HBDs) is applied successfully to highly enantioselective Prins cyclization reactions of a wide variety of simple alkenyl aldehydes. The optimal chiral catalysts were designed to withstand the strongly acidic reaction conditions and were found to induce rate accelerations of 2 orders of magnitude over reactions catalyzed by HCl alone. We propose that the combination of strong mineral acids and chiral hydrogen-bond-donor catalysts may represent a general strategy for inducing enantioselectivity in reactions that require highly acidic conditions.

| S-EPMC8717859 | biostudies-literature

Highly Stereoselective Glycosylation Reactions of Furanoside Derivatives via Rhenium (V) Catalysis.

Project description:A novel approach for the formation of anomeric carbon-functionalized furanoside systems was accomplished through the employment of an oxo-rhenium catalyst. The transformation boasts a broad range of nucleophiles including allylsilanes, enol ethers, and aromatics in addition to sulfur, nitrogen, and hydride donors, able to react with an oxocarbenium ion intermediate derived from furanosidic structures. The excellent stereoselectivities observed followed the Woerpel model, ultimately providing 1,3-cis-1,4-trans systems. In the case of electron-rich aromatic nucleophiles, an equilibration occurs at the anomeric center with the selective formation of 1,3-trans-1,4-cis systems. This anomalous result was rationalized through density functional theory calculations. Different oxocarbenium ions such as those derived from dihydroisobenzofuran, pyrrolidine, and oxazolidine heterocycles can also be used as a substrate for the oxo-Re-mediated allylation reaction.

| S-EPMC8279489 | biostudies-literature

Iodine-catalyzed prins cyclization of homoallylic alcohols and aldehydes.

Project description:The iodine-catalyzed Prins cyclization of homoallylic alcohols and aldehydes was investigated under metal-free conditions and without additives. Anhydrous conditions and inert atmosphere are not required. The reaction of 2-(3,4-dihydronaphthalen-1-yl)propan-1-ol and 21 aldehydes (aliphatic and aromatic) in CH₂Cl₂ in the presence of 5 mol % of iodine gave 1,4,5,6-tetrahydro-2H-benzo[f]isochromenes in 54%-86% yield. Under similar conditions, the Prins cyclization of six alcohols containing an endocyclic double bond (primary, secondary, or tertiary) led to dihydropyrans in 52%-91% yield. The acyclic homoallylic alcohols gave 4-iodo-tetrahydropyran in 29%-41% yield in the presence of 50 mol % of iodine. This type of substrate is the main limitation of the methodology. The relative configuration of the products was assigned by NMR and X-ray analysis. The mechanism and the ratio of the products are discussed, based on DFT calculations.

| S-EPMC6269844 | biostudies-literature

An aza-Prins cyclization approach to functionalized indolizidines from 2-allylpyrrolidines.

Project description:The stereoselective synthesis of a diverse set of functionalized indolizidine systems has been accomplished through the aza-Prins cyclization of 2-allylpyrrolidines. The condensation of aldehydes onto 2-allylpyrrolidines yields iminium ions that undergo highly diastereoselective aza-Prins cyclization, producing up to two stereogenic centers and two new rings in one step.

| S-EPMC3492938 | biostudies-literature

Rhenium Alkyne Catalysis: Sterics Control the Reactivity.

Project description:Metathesis reactions, including alkane, alkene, and alkyne metatheses, have their origins in the fundamental understanding of chemical reactions and the development of specialized catalysts. These reactions stand as transformative pillars in organic chemistry, providing efficient rearrangement of carbon-carbon bonds and enabling synthetic access to diverse and complex compounds. Their impact spans industries such as petrochemicals, pharmaceuticals, and materials science. In this work, we present a detailed mechanistic study of the Re(V) catalyzed alkyne metathesis through density functional theory calculations. Our findings are in agreement with the experimental evidence from Jia and co-workers and unveil critical factors governing catalyst performance. Our work not only enhances our understanding of alkyne metathesis but also contributes to the broader landscape of catalytic processes, facilitating the design of more efficient and selective transformations in organic synthesis.

| S-EPMC10988556 | biostudies-literature

Formal synthesis of (-)-kendomycin featuring a Prins-cyclization to construct the macrocycle.

Project description:The kendomycin skeleton was prepared by a highly convergent strategy in which the benzofuran fragment and the acyclic iodide fragment were prepared by standard methods and joined using a Suzuki coupling. The distinctive reaction in our approach was an intramolecular Prins cyclization that assembles the macrocyclic ring in good yield. Modeling studies demonstrate that the acyclic chain is predisposed for macrocycle formation. Ultimately, the product was correlated with one of Lee's advanced intermediates for a formal total synthesis of kendomycin.

| S-EPMC2697922 | biostudies-literature

Silyl enol ether Prins cyclization: diastereoselective formation of substituted tetrahydropyran-4-ones.

Project description:A diastereoselective synthesis of cis-2,6-disubstituted tetrahydropyran-4-ones was developed. The key step of this methodology, a silyl enol ether Prins cyclization, was promoted by a condensation reaction between a hydroxy silyl enol ether and an aldehyde to afford substituted tetrahydropyran-4-ones. The cyclization was tolerant of many functional groups, and the modular synthesis of the hydroxy silyl enol ether allowed for the formation of more than 30 new tetrahydropyran-4-ones with up to 97% yield and >95:5 dr. The cyclization step forms new carbon-carbon and carbon-oxygen bonds, as well as a quaternary center with good diastereoselectivity. The method provides a versatile route for the synthesis of substituted tetrahydropyrans.

| S-EPMC4168786 | biostudies-literature

Synthesis of Tetrahydroazepines through Silyl Aza-Prins Cyclization Mediated by Iron(III) Salts.

Project description:A new methodology for the synthesis of seven-membered unsaturated azacycles (tetrahydroazepines) was developed. It is based on the powerful aza-Prins cyclization in combination with the Peterson-type elimination reaction. In a single reaction step, a C-N, C-C bond and an endocyclic double bond are formed. Under mild reaction conditions and using iron(III) salts as sustainable catalysts, tetrahydroazepines with different degrees of substitution are obtained directly and efficiently. DFT calculations supported the proposed mechanism.

| S-EPMC9442639 | biostudies-literature

A tandem isomerization/prins strategy: iridium(III)/Bronsted acid cooperative catalysis.

Project description:Working together: A mild and efficient isomerization/protonation sequence generates pyran-fused indoles by cooperative catalysis between cationic iridium(III) and Bi(OTf)3 . Three distinct cyclization manifolds lead to the corresponding bioactive scaffolds in good yields. In addition, N-substituted indoles can be synthesized enantioselectively in the presence of a chiral phosphate.

| S-EPMC3905988 | 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