Browse
Submit Data
Databases
API
Help

Dataset Information

29 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Enantioselective Inverse-Electron Demand Aza-Diels-Alder Reaction: ipso,α-Selectivity of Silyl Dienol Ethers.

ABSTRACT: A highly efficient enantioselective inverse-electron-demand aza-Diels-Alder reaction between aza-sulfonyl-1-aza-1,3-butadienes and silyl (di)enol ethers has been developed. The presented methodology allows the synthesis of benzofuran-fused 2-piperidinol derivatives with three contiguous stereocenters in a highly selective manner, as even the hemiaminal center is completely stereocontrolled. Density functional theory (DFT) calculations support that the hydrogen-bond donor-based bifunctional organocatalyst selectively triggers the reaction through the ipso,α-position of the dienophile, in contrast to the reactivity observed for dienolates in situ generated from β,γ-unsaturated derivatives. Moreover, the calculations have clarified the mechanism of the reaction and the ability of the hydrogen-bond donor core to hydrolyze selectively the E isomer of the dienol ether. Furthermore, to demonstrate the applicability of silyl enol ethers as nucleophiles in the asymmetric synthesis of interesting benzofuran-fused derivatives, the catalytic system has also been implemented for the highly efficient installation of an aromatic ring in the piperidine adducts.

SUBMITTER: Laina-Martin V

PROVIDER: S-EPMC8491166 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Diastereo- and Enantioselective Inverse-Electron-Demand Diels-Alder Cycloaddition between 2-Pyrones and Acyclic Enol Ethers.

Project description:A broadly applicable diastereo- and enantioselective inverse-electron-demand Diels-Alder reaction of 2-pyrones and acyclic enol ethers is reported herein. Using a copper(II)-BOX catalytic system, bridged bicyclic lactones are obtained in very high yields (up to 99 % yield) and enantioselectivities (up to 99 % ee) from diversely substituted 2-pyrones and acyclic enol ethers. Mechanistic experiments as well as DFT calculations indicate the occurrence of a stepwise mechanism. The synthetic potential of the bridged bicyclic lactones is showcased by the enantioselective synthesis of polyfunctional cyclohexenes and cyclohexadienes, as well as a carbasugar unit.

| S-EPMC9826153 | biostudies-literature

Orthogonal Catalysis for an Enantioselective Domino Inverse-Electron Demand Diels-Alder/Substitution Reaction.

Project description:An enantioselective domino process for the synthesis of substituted 1,2-dihydronaphthalenes has been developed by the combination of chiral amines and a bidentate Lewis acid in an orthogonal catalysis. This new method is based on an inverse electron-demand Diels-Alder and a subsequent group exchange reaction. An enamine is generated in situ from an aldehyde and a chiral secondary amine catalyst that reacts with phthalazine, activated by the coordination to a bidentate Lewis acid catalyst. The absolute configuration of the product is controlled by chiral information provided by the amine. The formed ortho-quinodimethane intermediate is then transformed via a group exchange reaction with thiols. The new method shows a broad scope and tolerates a wide range of functional groups with enantiomeric ratios up to 91 : 9. All-in-all, this enantioselective synthesis tool provides an easy access to complex 1,2-dihydronaphthalenes starting from readily available phthalazine, aldehydes and thiols in a combinatorial way.

| S-EPMC9299787 | biostudies-literature

An intramolecular inverse electron demand Diels-Alder approach to annulated ?-carbolines.

Project description:Intramolecular inverse electron demand cycloadditions of isatin-derived 1,2,4-triazines with acetylenic dienophiles tethered by amidations or transesterifications proceed in excellent yields to produce lactam- or lactone-fused ?-carbolines. Beginning with various isatins and alkynyl dienophiles, a pilot-scale library of eighty-eight ?-carbolines was prepared by using this robust methodology for biological evaluation.

| S-EPMC3388871 | biostudies-other

Unconventional exo selectivity in thermal normal-electron-demand Diels-Alder reactions.

Project description:The Diels-Alder reaction is a useful tool for generating functionalized chiral molecules through the concerted cycloaddition of dienes and dienophiles leading to six-membered rings. Traditionally, the selective predictions of the products rely heavily on consideration of the secondary orbital interactions that stabilize the endo pathway. However, there remain some basic examples defying this notion and produce the exo-isomer as major product. Here we systematically evaluated of the structural features driving exo selectivity in thermal normal-electron-demand Diels-Alder reactions. Substitution at the Cβ position and the size and electronegativity of the electron-withdrawing group of the dienophile are contributing factors. Experimental and computational studies both point toward the steric and electrostatic forces between the substituents in both the diene and the dienophile that increase the likelihood of the exo pathway. For these substrates, the dominance of the endo pathway is reduced by transition state distortions and poor structural alignments of the reacting partners. We also noted the tilt of the dienophile with respect to the diene causing steric strain on the functionalities at the more advanced bond forming carbon-carbon position of the endo transition state. Insights into such factors may benefit synthetic planning and asserting control over this important named reaction.

| S-EPMC5059706 | biostudies-other

Lewis acid catalyzed inverse-electron-demand Diels-Alder reaction of tropones.

Project description:Lewis acid catalyzed inverse-electron-demand Diels-Alder reaction of tropone derivatives was developed. Up to 97% ee was obtained for the chiral dinucleus BINOL-aluminum complex catalyzed reaction between tropones and ketene diethyl acetal to give bicyclo[3.2.2] ring structures, which opens up a unique way of making chiral seven-membered rings.

| S-EPMC2810398 | biostudies-literature

Enantioselective (formal) aza-Diels-Alder reactions with non-Danishefsky-type dienes.

Project description:Enantioselective (formal) aza-Diels-Alder reactions between acylhydrazones and non-Danishefsky-type dienes have been developed. The reactions are promoted by a simple and economical chiral silicon Lewis acid and are typically conducted at ambient temperature. Both glyoxylate- and aliphatic aldehyde-derived hydrazones may be employed, as may variously substituted dienes, leading to the synthesis of a diverse array of tetrahydropyridines with good to excellent levels of enantioselectivity.

| S-EPMC2918383 | biostudies-literature

Hyperconjugative Antiaromaticity Activates 4H-Pyrazoles as Inverse-Electron-Demand Diels-Alder Dienes.

Project description:The Diels-Alder reactivity of 4,4-difluoro-3,5-diphenyl-4H-pyrazole was investigated experimentally and computationally with endo-bicyclo[6.1.0]non-4-yne. The computationally predicted rate enhancement from hyperconjugative antiaromaticity induced by fluorination of cyclopentadienes at the 5-position extends to five-membered heterocyclic dienes containing a saturated center. 4,4-Difluoro-4H-pyrazoles are new electron-deficient dienes with rapid reactivities toward strained alkynes.

| S-EPMC7015664 | biostudies-literature

Tetrazine ligation: fast bioconjugation based on inverse-electron-demand Diels-Alder reactivity.

Project description:Described is a bioorthogonal reaction that proceeds with unusually fast reaction rates without need for catalysis: the cycloaddition of s-tetrazine and trans-cyclooctene derivatives. The reactions tolerate a broad range of functionality and proceed in high yield in organic solvents, water, cell media, or cell lysate. The rate of the ligation between trans-cyclooctene and 3,6-di-(2-pyridyl)-s-tetrazine is very rapid (k2 2000 M-1 s-1). This fast reactivity enables protein modification at low concentration.

| S-EPMC2653060 | biostudies-literature

Approach Matters: The Kinetics of Interfacial Inverse-Electron Demand Diels-Alder Reactions.

Project description:Rapid and quantitative click functionalization of surfaces remains an interesting challenge in surface chemistry. In this regard, inverse electron demand Diels-Alder (IEDDA) reactions represent a promising metal-free candidate. Herein, we reveal quantitative surface functionalization within 15 min. Furthermore, we report the comprehensive effects of substrate stereochemistry, surrounding microenvironment and substrate order on the reaction kinetics as obtained by surface-bound mass spectrometry (DART-HRMS).

| S-EPMC5637934 | biostudies-literature

Scope of the inverse electron demand Diels-Alder reactions of 1,2,3-triazine.

Project description:An examination of the scope of the inverse electron demand Diels-Alder reactions of the parent unsubstituted 1,2,3-triazine is described including the first report of its unique capabilities for participating in previously unexplored [4 + 2] cycloaddition reactions with heterodienophiles.

| S-EPMC3093666 | 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