Browse
Submit Data
Databases
API
Help

Dataset Information

36 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Gold(I)-catalyzed cascade cyclization of allenyl epoxides.

ABSTRACT: Cationic gold(I) phosphite catalysts activate allenes for epoxide cascade reactions. The system is tolerant of numerous functional groups (sulfones, esters, ethers, sulfonamides) and proceeds at room temperature in dichloromethane. The cyclization pathway is sensitive to the substitution pattern of the epoxide and the backbone structure of the A-ring. It is capable of producing medium-ring ethers, fused 6-5 bicyclic, and linked pyran-furan structures. The resulting cycloisomers are reminiscent of structures found in numerous polyether natural products.

SUBMITTER: Tarselli MA

PROVIDER: S-EPMC2742359 | biostudies-literature | 2009 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Gold(I)-catalyzed cascade cyclization of allenyl epoxides.

Tarselli Michael A MA Zuccarello J Lucas JL Lee Stephen J SJ Gagné Michel R MR

Organic letters 20090801 15

Cationic gold(I) phosphite catalysts activate allenes for epoxide cascade reactions. The system is tolerant of numerous functional groups (sulfones, esters, ethers, sulfonamides) and proceeds at room temperature in dichloromethane. The cyclization pathway is sensitive to the substitution pattern of the epoxide and the backbone structure of the A-ring. It is capable of producing medium-ring ethers, fused 6-5 bicyclic, and linked pyran-furan structures. The resulting cycloisomers are reminiscent o ...[more]

PMID: 19588972

Similar Datasets

Gold-catalyzed cyclization of allenyl acetal derivatives.

Project description:The gold-catalyzed transformation of allenyl acetals into 5-alkylidenecyclopent-2-en-1-ones is described. The outcome of our deuterium labeling experiments supports a 1,4-hydride shift of the resulting allyl cationic intermediates because a complete deuterium transfer is observed. We tested the reaction on various acetal substrates bearing a propargyl acetate, giving 4-methoxy-5-alkylidenecyclopent-2-en-1-ones 4 via a degradation of the acetate group at the allyl cation intermediate.

| S-EPMC3778408 | biostudies-literature

Cyclization cascade of allenyl azides: a dual mechanism.

Project description:A density functional theory based computational approach to describing the mechanistic course of the allene azide cycloaddition cascade sequence has been developed. The results of these calculations permit characterization of key reactive intermediates (diradicals and/or indolidenes) and explain the different behaviors observed in the experimental studies between conjugated and nonconjugated species. Furthermore, computational analysis of certain intermediates offer insight into issues of regioselectivity and stereoselectivity in cases where different reaction channels are in competition, suggesting suitable substitutions to achieve a single regioisomer in the indole synthesis via azide-allene cyclization.

| S-EPMC2527537 | biostudies-literature

Gold and BINOL-phosphoric acid catalyzed enantioselective hydroamination/N-sulfonyliminium cyclization cascade.

Project description:A highly enantioselective hydroamination/N-sulfonyliminium cyclization cascade is reported using a combination of gold(I) and chiral phosphoric acid catalysts. An initial 5-exo-dig hydroamination and a subsequent phosphoric acid catalyzed cyclization process provide access to complex sulfonamide scaffolds in excellent yield and high enantiocontrol. The method can be extended to lactam derivatives, with excellent yields and enantiomeric excesses of up to 93% ee.

| S-EPMC3931332 | biostudies-literature

Gold(i)-catalyzed stereoselective cyclization of 1,3-enyne aldehydes by a 1,3-acyloxy migration/Nazarov cyclization/aldol addition cascade.

Project description:Stereoselective synthesis of bicyclo[3.3.0]octenones from chiral 1,3-enyne aldehydes bearing propargylic acetates is described. The method is based on a Au(i)-catalyzed domino sequence with concomitant transfer of chirality involving 1,3-acyloxy migration followed by Nazarov cyclization and an unprecedented aldol addition. The method furnishes densely functionalized bicyclic structures in high yields, with up to 97% ee and good diastereoselectivity.

| S-EPMC6839590 | biostudies-literature

Gold(I)-catalyzed intramolecular cyclization/intermolecular cycloaddition cascade as a fast track to polycarbocycles and mechanistic insights.

Project description:Metal carbene is an active synthetic intermediate, which has shown versatile applications in synthetic chemistry. Although a variety of catalytic methods have been disclosed for the generation of carbene species from different precursors, there is an increasing demand for the development of efficient and practical approaches for the in-situ formation of metal carbene intermediates with structural diversity and unrevealed reactivity. Herein we report a gold-catalyzed cascade protocol for the assembly of polycarbocyclic frameworks in high yields under mild reaction conditions. Mechanistic studies indicate that the unique β-aryl gold-carbene species, generated via gold-promoted 6-endo-dig diazo-yne cyclization, is the key intermediate in this reaction, followed by a [4 + 2]-cycloaddition with external alkenes. In comparison to the well-documented metal carbene cycloadditions, this carbene intermediate serves as a 4-C synthon in a cycloaddition reaction. A variety of elusive π-conjugated polycyclic hydrocarbons (CPHs) with multiple substituents are readily accessible from the initially generated products by a mild oxidation procedure.

| S-EPMC7896061 | biostudies-literature

Gold catalyzed cyclization of alkyne-tethered dihydropyrimidones.

Project description:Dihydropyrimidones are an important class of biologically active heterocycles accessible from the multicomponent Biginelli condensation. Further manipulation of the dihydropyrimidone skeleton gives access to unique heterocycles. Presented herein is a Au-catalyzed cyclization of alkyne-tethered dihydropyrimidones to yield pyridopyrimidones.

| S-EPMC4251731 | biostudies-literature

Palladium-catalyzed carbonylative cyclization/arylation cascade for 2-aroylindolizine synthesis.

Project description:An efficient synthesis of densely substituted 2-aroylindolizines via the palladium-catalyzed carbonylative cyclization/arylation is reported. This transformation proceeds via the 5-endo-dig cyclization of 2-propargylpyridine triggered by an aroyl Pd complex. It produced diversely substituted 2-aroylindolizines in good to excellent yields.

| S-EPMC3582654 | biostudies-literature

Gold-catalyzed double migration-benzannulation cascade toward naphthalenes.

Project description:A novel gold(I)-catalyzed cycloisomerization of propargylic esters leading to unsymmetrically substituted naphthalenes has been developed. This cascade reaction involves an unprecedented tandem sequence of 1,3- and 1,2-migration of two different migrating groups. It is believed that this transformation likely proceeds via the formation of 1,3-diene intermediate or its precursor, which upon cyclization and aromatization steps transforms into the naphthalene core.

| S-EPMC3679922 | biostudies-literature

Palladium-catalyzed intramolecular carbopalladation/cyclization cascade: access to polycyclic N-fused heterocycles.

Project description:An efficient palladium-catalyzed intramolecular carbopalladation/cyclization cascade toward tetra- and pentacyclic N-fused heterocycles has been developed. This transformation proceeds via the palladium-catalyzed coupling of aryl halides with internal propargylic esters or ethers followed by the 5-endo-dig cyclization leading to polycyclic pyrroloheterocycles in moderate to excellent yields.

| S-EPMC3131228 | biostudies-literature

Enantioselective copper-catalyzed construction of aryl pyrroloindolines via an arylation-cyclization cascade.

Project description:An enantioselective arylation-cyclization cascade has been accomplished using a combination of diaryliodonium salts and asymmetric copper catalysis. These mild catalytic conditions provide a new strategy for the enantioselective construction of pyrroloindolines, an important alkaloid structural motif that is commonly found among biologically active natural products.

| S-EPMC3392034 | 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