Browse
Submit Data
Databases
API
Help

Dataset Information

39 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

5-Hydroxyindoles by intramolecular alkynol-furan diels-alder cycloaddition.

ABSTRACT: A convergent approach provides a convenient access to synthetically and biologically useful 3,4-disubstituted 5-hydroxyindoles. The one-pot procedure uses microwave heating to initiate an intramolecular [4 + 2]-cycloaddition of an alkynol segment onto a furan followed by a fragmentation, aromatization, and N-Boc deprotection cascade. Yields range from 15 to 74%, with aromatic substituents providing better conversions. 4-Trimethylsilylated analogues undergo a 1,3-silatropic rearrangement to give the O-TMS ethers.

SUBMITTER: LaPorte M

PROVIDER: S-EPMC3684082 | biostudies-literature | 2013 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

5-Hydroxyindoles by intramolecular alkynol-furan diels-alder cycloaddition.

LaPorte Matthew M Hong Ki Bum KB Xu Jie J Wipf Peter P

The Journal of organic chemistry 20121116 1

A convergent approach provides a convenient access to synthetically and biologically useful 3,4-disubstituted 5-hydroxyindoles. The one-pot procedure uses microwave heating to initiate an intramolecular [4 + 2]-cycloaddition of an alkynol segment onto a furan followed by a fragmentation, aromatization, and N-Boc deprotection cascade. Yields range from 15 to 74%, with aromatic substituents providing better conversions. 4-Trimethylsilylated analogues undergo a 1,3-silatropic rearrangement to give ...[more]

PMID: 23136970

Similar Datasets

Intramolecular diels-alder/1,3-dipolar cycloaddition cascade of 1,3,4-oxadiazoles.

Project description:Full details of a systematic exploration of the intramolecular [4 + 2]/[3 + 2] cycloaddition cascade of 1,3,4-oxadiazoles are disclosed in which the scope and utility of the reaction are defined.

| S-EPMC2587417 | biostudies-literature

A microwave assisted intramolecular-furan-Diels-Alder approach to 4-substituted indoles.

Project description:The key steps of a versatile new protocol for the convergent synthesis of 3,4-disubstituted indoles are the addition of an alpha-lithiated alkylaminofuran to a carbonyl compound, a microwave-accelerated intramolecular Diels-Alder cycloaddition and an in situ double aromatization reaction.

| S-EPMC2736609 | biostudies-literature

Formal [2 + 2 + 2] cycloaddition strategy based on an intramolecular propargylic ene reaction/Diels-Alder cycloaddition cascade.

Project description:A formal, metal-free, [2 + 2 + 2] cycloaddition strategy is described based on a cascade of two pericyclic processes. The first step involves an intramolecular propargylic ene reaction of a 1,6-diyne to generate a vinylallene, which then reacts in an inter- or intramolecular Diels-Alder reaction with an alkenyl or alkynyl dienophile. Reactions involving unsymmetrical alkenyl and alkynyl dienophiles proceed with good to excellent regioselectivity, and the diastereoselectivity in the Diels-Alder step is also high, with endo cycloadducts produced as the exclusive products of the reaction. In the case of alkynyl dienophiles, [4 + 2] cycloaddition initially generates an isotoluene-type intermediate that isomerizes to the isolated aromatic product upon exposure to a catalytic amount of DBU at room temperature. The mechanism of several earlier fully intramolecular related transformations have been shown to involve an analogous process rather than the diradical-mediated pathways proposed previously.

| S-EPMC2924204 | biostudies-literature

Assembly of the isoindolinone core of muironolide A by asymmetric intramolecular Diels-Alder cycloaddition.

Project description:The hexahydro-1H-isoindolin-1-one core of muironolide A was prepared by asymmetric intramolecular Diels-Alder cycloaddition using a variant of the MacMillan organocatalyst which sets the C4,C5 and C11 stereocenters.

| S-EPMC4000739 | biostudies-literature

Intramolecular Diels-Alder reactions of cyclopropenone ketals.

Project description:The first intramolecular cycloaddition reactions of cyclopropenone ketals with tethered electron-deficient, electron-rich, and neutral 1-substituted dienes are reported, constituting inverse electron demand, normal, and neutral Diels-Alder reactions, that provide exclusively the exo [4 + 2] cycloaddition products without the intervention of [1 + 2], [3 + 2], or [3 + 4] cycloadducts in reactions whose courses do not depend on the reaction conditions, the diene activating substituent, or the nature of the tethering.

| S-EPMC2912946 | biostudies-literature

CYCLOADDITION REACTIONS OF AZIDE, FURAN, AND PYRROLE UNITS WITH BENZYNES GENERATED BY THE HEXADEHYDRO-DIELS-ALDER (HDDA) REACTION.

Project description:Benzynes can be generated by the intramolecular thermal cycloisomerization of triynes-the title HDDA reaction. We report here that these can be trapped by cycloaddition reaction with trimethylsilyl azide (1,3-dipolar) or a furan or pyrrole (4+2 Diels-Alder).

| S-EPMC4045115 | biostudies-literature

Mechanism of the Intramolecular Hexadehydro-Diels-Alder Reaction.

Project description:Theoretical analysis of the mechanism of the intramolecular hexadehydro-Diels-Alder (HDDA) reaction, validated against prior and newly measured kinetic data for a number of different tethered yne-diynes, indicates that the reaction proceeds in a highly asynchronous fashion. The rate-determining step is bond formation at the alkyne termini nearest the tether, which involves a transition-state structure exhibiting substantial diradical character. Whether the reaction then continues to close the remaining bond in a concerted fashion or in a stepwise fashion (i.e., with an intervening intermediate) depends on the substituents at the remaining terminal alkyne positions. Computational modeling of the HDDA reaction is complicated by the significant diradical character that arises along the reaction coordinate, which leads to instabilities in both restricted singlet Kohn-Sham density functional theory (DFT) and coupled cluster theory based on a Hartree-Fock reference wave function. A consistent picture emerges, however, from comparison of broken-symmetry DFT calculations and second-order perturbation theory based on complete-active-space self-consistent-field (CASPT2) calculations.

| S-EPMC4729778 | biostudies-literature

Intramolecular Diels-Alder reactions of siloxacyclopentene constrained trienes.

Project description:The synthesis of siloxacyclopentene-constrained trienes 7 and 10 and studies of their IMDA cycloadditions are described. The use of appropriately chosen thermal or Lewis acid conditions allows for cycloadducts 3-6 to be obtained with high levels of diastereoselectivity. These adducts possess trans-relationships between the hydroxyl group and the adjacent ring fusion proton, a stereochemical relationship not previously attainable in IMDA reactions.

| S-EPMC2504012 | biostudies-literature

Enantioselective Diels-Alder-lactamization organocascades employing a furan-based diene.

Project description:α,β-Unsaturated acylammonium salts are useful dienophiles enabling highly enantioselective and stereodivergent Diels-Alder-initiated organocascades with furan-based dienes. Complex polycyclic systems can thus be obtained from readily prepared dienes, commodity acid chlorides, and a chiral isothiourea organocatalyst under mild conditions. We describe the use of furan-based dienes bearing pendant sulfonamides leading to the generation of oxa-bridged, trans-fused tricyclic γ-lactams. This process constitutes the first highly enantio- and diastereoselective, organocatalytic Diels-Alder cycloadditions with these typically problematic dienes due to their reversibility. Computational studies suggest that the high diastereoselectivity with these furan dienes may be due to a reversible Diels-Alder cycloaddition for the endo adducts. In addition, the utility of this methodology is demonstrated through a concise approach to a core structure with similarity to the natural product isatisine A and a nonpeptidyl ghrelin-receptor inverse agonist.

| S-EPMC5522755 | biostudies-literature

Hetero-Diels-Alder Cycloaddition with RAFT Polymers as Bioconjugation Platform.

Project description:We introduce the bioconjugation of polymers synthesized by RAFT polymerization, bearing no specific functional end group, by means of hetero-Diels-Alder cycloaddition through their inherent terminal thiocarbonylthio moiety with a diene-modified model protein. Quantitative conjugation occurs over the course of a few hours, at ambient temperature and neutral pH, and in the absence of any catalyst. Our technology platform affords thermoresponsive bioconjugates, whose aggregation is solely controlled by the polymer chains.

| S-EPMC7693046 | 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