Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Unexpected catalytic reactions of silyl-protected enol diazoacetates with nitrile oxides that form 5-arylaminofuran-2(3H)-one-4-carboxylates.

ABSTRACT: Silyl-protected enol diazoacetates undergo dirhodium(II)-catalyzed reactions with nitrile oxides to form acid-labile ketenimines via dipolar cycloaddition of nitrile oxides to a donor/acceptor cyclopropene and Lossen rearrangement of the dipolar adduct; acid catalysis converts the ketenimine to the furan product.

SUBMITTER: Xu X

PROVIDER: S-EPMC3273040 | biostudies-literature | 2012 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Unexpected catalytic reactions of silyl-protected enol diazoacetates with nitrile oxides that form 5-arylaminofuran-2(3H)-one-4-carboxylates.

Xu Xinfang X Shabashov Dmitry D Zavalij Peter Y PY Doyle Michael P MP

Organic letters 20120124 3

Silyl-protected enol diazoacetates undergo dirhodium(II)-catalyzed reactions with nitrile oxides to form acid-labile ketenimines via dipolar cycloaddition of nitrile oxides to a donor/acceptor cyclopropene and Lossen rearrangement of the dipolar adduct; acid catalysis converts the ketenimine to the furan product. ...[more]

PMID: 22272728

Similar Datasets

Substrate-dependent divergent outcomes from catalytic reactions of silyl-protected enol diazoacetates with nitrile oxides: azabicyclo[3.1.0]hexanes or 5-arylaminofuran-2(3H)-ones.

Project description:Dirhodium(II)-catalyzed reactions of silyl-protected enol diazoacetates with nitrile oxides exhibit high nitrile oxide substituent dependence in the production rearrangement products via dipolar cycloaddition and either the Neber rearrangement or the Lossen rearrangement.

| S-EPMC3377374 | biostudies-literature

Synthesis of 2-substituted 7-hydroxybenzofuran-4-carboxylates via addition of silyl enol ethers to o-benzoquinone esters.

Project description:Mukaiyama Michael addition of silyl enol ethers 13 to the 1,2-quinone-4-carboxylate 6 (formed in situ by oxidation of the catechol ester 8) afforded the 2-subsituted 7-hydroxybenzofuran-4-carboxylates 14 in fair to good yields. Alkyl and aryl systems work well, but highly electron-rich silyl enol ethers could not be used because of competing oxidation.

| S-EPMC2784895 | biostudies-literature

Nickel-Catalyzed Reductive Conjugate Addition of Primary Alkyl Bromides to Enones To Form Silyl Enol Ethers.

Project description:Conjugate addition of organometallic reagents to enones to form silyl enol ether products is a versatile method to difunctionalize activated olefins, but the organometallic reagents required can be limiting. The reductive cross-electrophile coupling of unhindered primary alkyl bromides with enones and chlorosilanes to form silyl enol ether products is catalyzed by a nickel-complexed ortho-brominated terpyridine ligand. The conditions are compatible with a variety of cyclic/acyclic enones and functional groups.

| S-EPMC5260806 | biostudies-literature

Photoredox-catalyzed silyldifluoromethylation of silyl enol ethers.

Project description:A method for the light-mediated fluoroalkylation of silyl enol ethers with (bromodifluoromethyl)trimethylsilane followed by a reduction of the primary products with sodium borohydride is described. An 18 W, 375 nm LED was used as the light source. The reaction is performed in the presence of a gold photocatalyst, which effects the generation of a (trimethylsilyl)difluoromethyl radical via cleavage of the carbon-bromine bond.

| S-EPMC7356207 | biostudies-literature

FLP-Catalyzed Transfer Hydrogenation of Silyl Enol Ethers.

Project description:Herein we report the first catalytic transfer hydrogenation of silyl enol ethers. This metal free approach employs tris(pentafluorophenyl)borane and 2,2,6,6-tetramethylpiperidine (TMP) as a commercially available FLP catalyst system and naturally occurring γ-terpinene as a dihydrogen surrogate. A variety of silyl enol ethers undergo efficient hydrogenation, with the reduced products isolated in excellent yields (29 examples, 82 % average yield).

| S-EPMC6207922 | biostudies-literature

Synthesis of substituted pyrazoles via tandem cross-coupling/electrocyclization of enol triflates and diazoacetates.

Project description:The synthesis of 3,4,5-trisubstituted pyrazoles via a tandem catalytic cross-coupling/electrocyclization of enol triflates and diazoacetates is presented. The initial scope of this methodology is demonstrated on a range of differentially substituted acyclic and cyclic enol triflates as well as an elaborated set of diazoacetates to provide the corresponding pyrazoles with a high degree of structural complexity.

| S-EPMC3155889 | biostudies-literature

Vinylogous reactivity of enol diazoacetates with donor-acceptor substituted hydrazones. Synthesis of substituted pyrazole derivatives.

Project description:A regiospecific synthesis of multifunctional pyrazoleshas been developed from a cascade process triggered by Rh(II)-catalyzed dinitrogen extrusion from enol diazoacetates with vinylogous nucleophilic addition followed by Lewis acid catalyzed cyclization and aromatization.

| S-EPMC3574190 | 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

Oxygenated Cyclopentenones via the Pauson-Khand Reaction of Silyl Enol Ether Substrates.

Project description:We report here the application of silyl enol ether moieties as efficient alkene coupling partners within cobalt-mediated intramolecular Pauson-Khand reactions. This cyclization strategy delivers synthetically valuable oxygenated cyclopentenone products in yields of ≤93% from both ketone- and aldehyde-derived silyl enol ethers, incorporates both terminal and internal alkyne partners, and delivers a variety of decorated systems, including more complex tricyclic structures. Facile removal of the silyl protecting group reveals oxygenated sites for potential further elaboration.

| S-EPMC9016766 | biostudies-literature

Enantioselective α-functionalizations of ketones via allylic substitution of silyl enol ethers.

Project description:The enantioselective construction of carbon-heteroatom and carbon-carbon bonds that are alpha to ketones leads to the formation of substructures that are ubiquitous in natural products, pharmaceuticals and agrochemicals. Traditional methods to form such bonds have relied on combining ketone enolates with electrophiles. Reactions with heteroatom-based electrophiles require special reagents in which the heteroatom, which is typically nucleophilic, has been rendered electrophilic by changes to the oxidation state. The resulting products usually require post-synthetic transformations to unveil the functional group in the final desired products. Moreover, different catalytic systems are typically required for the reaction of different electrophiles. Here, we report a strategy for the formal enantioselective α-functionalization of ketones to form products containing a diverse array of substituents at the alpha position with a single catalyst. This strategy involves an unusual reversal of the role of the nucleophile and electrophile to form C-N, C-O, C-S and C-C bonds from a series of masked ketone electrophiles and a wide range of conventional heteroatom and carbon nucleophiles catalysed by a metallacyclic iridium catalyst.

| S-EPMC6347495 | 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