Indoles

Distribution by Scientific Domains
Distribution within Chemistry


Selected Abstracts


Iron,Palladium Association in the Preparation of Indoles and One-Pot Synthesis of Bis(indolyl)methanes

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 32 2007
Vincent Terrasson
Abstract Indoles were prepared by annulation of the parent alkynylanilines with the use of a new FeCl3,PdCl2 catalytic combination. High yields were obtained by using low loadings of the transition-metal complex (FeCl3,PdCl2: 2 and 1 mol-%, respectively). One-pot accesses to bis(indolyl)methanes and trisubstituted indoles through annulation/Friedel,Crafts alkylation and annulation/1,4-Michael addition sequences, in which FeCl3 acts both as a cooxidant and a Lewis acid are described.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]


Facile Creation of 3-Indolyl-3-hydroxy-2-oxindoles by an Organocatalytic Enantioselective Friedel,Crafts Reaction of Indoles with Isatins

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 5 2010
Jing Deng
Abstract The first direct enantioselective Friedel,Crafts reaction of indoles with isatins has been developed. The process is catalyzed by simple cupreine under mild reaction conditions and affords synthetically and biologically interesting, chiral 3-indolyl-3-hydroxy-2-oxindoles in good yields (68,97%) and with high enantioselectivities (76,91%). [source]


Direct Synthesis of Dihydrobenzo[a]carbazoles via Palladium-Catalyzed Domino Annulation of Indoles

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 2-3 2010
Farnaz Jafarpour
Abstract A straightforward one-step synthesis of annulated indoles via palladium-catalyzed, norbornene-mediated sequential intermolecular aryl ortho -alkylation/intramolecular indole CH activation has been devised. This method provides an efficient route to a wide variety of substituted 6,11-dihydro-5H -benzo[a]carbazoles from readily accessible 3-bromoalkylindoles and iodoarenes. [source]


Trapping of Active Methylene Intermediates with Alkenes, Indoles or Thiols: Towards Highly Selective Multicomponent Reactions

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 18 2009
Yanlong Gu
Abstract In this paper, a basic method to access new multicomponent reactions (MCRs) is reported. The mechanism of these MCRs is based on the trapping of methylene intermediates, formed in situ by reaction of formaldehyde with electron-rich carbons, with alkene, thiol or indole derivatives. According to our strategy, a wide range of valuable skeletons has been obtained in a one-pot reaction, thus allowing a minimization of waste, cost and labor. The presented methodology exhibits a broad substrate scope and electron-rich carbons in the ,-position of a hydroxy or carbonyl group were found to be particularly efficient. More generally, this work offers new tools for creating molecular complexity and diversity from one of the simplest organic building blocks, formaldehyde. [source]


Iridium-Catalyzed Selective Synthesis of 4-Substituted Benzofurans and Indoles via Directed Cyclodehydration

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 17 2009
Kyoji Tsuchikama
Abstract A directed cyclization-dehydration cascade of ,-aryloxy ketones and ,-arylamino ketones was efficiently catalyzed by a cationic iridium-BINAP complex, which afforded various types of 4-substituted benzofurans and indoles in high yields with complete regioselectivity. The newly developed protocol also enabled the enantioselective preparation of chiral 4-acetyloxindole using a chiral iridium catalyst. [source]


Synthesis of Functionalized Indoles with an ,-Stereogenic Ketone Moiety Through an Enantioselective Friedel,Crafts Alkylation with (E)-1,4-Diaryl-2-butene-1,4-diones

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2009
Gonzalo Blay
Abstract Chiral complexes of BINOL-based ligands with hafnium tert -butoxide catalyze the enantioselective Friedel,Crafts alkylation of indoles with (E)-1,4-diaryl-2-butene-1,4-diones at room temperature, with good yields and ee up to 94%. Hafnium(IV) was found to be a more effective Lewis acid than other frequently used metal ions such as titanium(IV) or zirconium(IV). Unlike the enantioselective Friedel,Crafts alkylation of indoles with ,,,-unsaturated compounds where the stereogenic center is generated in the ,-position to a carbonyl group, the Friedel,Crafts alkylation with 2-butene-1,4-diones described here generates an ,-stereogenic center with respect to one of the carbonyl groups. This can be regarded as an inversion of the normal reactivity pattern or umpolung. The enantioselective Friedel,Crafts alkylation of indoles with (E)-4-oxo-4-phenylbutenoates using a zirconium(IV)-BINOL catalyst is also reported. This reaction takes place regioselectively at the carbon in the ,-position to the ketone carbonyl group, generating an ,-ester stereogenic center. [source]


Gold-Catalyzed Intermolecular Reactions of (Z)-Enynols with Indoles for the Construction of Dihydrocyclohepta[b]indole Skeletons through a Cascade Friedel,Crafts/Hydroarylation Sequence

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2009
Yuhua Lu
Abstract An efficient domino approach for the synthesis of indole-fused carbocycles and their analogues from the reactions of suitably substituted (Z)-enynols with indoles or pyrroles under mild reaction conditions was developed. This methodology is realized by a tandem reaction using Au/Ag catalysts, which could catalyze both of the Friedel,Crafts and the hydroarylation reaction in the same vessel. [source]


Copper-Catalyzed N -Arylation/Hydroamin(d)ation Domino Synthesis of Indoles and its Application to the Preparation of a Chek1/KDR Kinase Inhibitor Pharmacophore

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 7-8 2009
Lutz Ackermann
Abstract Inexpensive copper catalysts allow for efficient syntheses of N -aryl-, N -acyl-, or N -H-(aza)indoles starting from ortho -alkynylbromoarenes. The broad scope of this domino N -arylation/hydroamin(d)ation process is highlighted by the synthesis of highly functionalized indoles, as well as of a Chek1/KDR inhibitor pharmacophore. [source]


An Efficient Enantioselective Method for Asymmetric Friedel,Crafts Alkylation of Indoles with ,,,-Unsaturated Aldehydes

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 5 2009
Liang Hong
Abstract The Lewis base-Lewis base bifunctional catalytic system has been developed and successfully applied to the asymmetric Friedel,Crafts alkylation of indoles with ,,,-unsaturated aldehydes. The reactions are promoted by chiral diphenylprolinol trimethylsilyl ether in the presence of triethylamine. By this protocol, optically active 3-substituted indoles can be obtained in an organocatalytic process that is free of Lewis or protic acid in high yields with up to 98% ee. Besides, this reaction could be carried out on a gram scale without any loss in the enantioselectivity. [source]


Chiral Phosphoric Acid-Catalyzed Enantioselective Aza-Friedel,Crafts Reaction of Indoles

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2007
Masahiro Terada
Abstract A highly enantioselective 1,2-aza-Friedel,Crafts reaction of N - tert -butyldimethylsilylindole with N - tert -butoxycarbonyl aromatic imines is demonstrated using a BINOL-derived monophosphoric acid catalyst. The present approach provides efficient access to 3-indolylmethaneamines with aryl substituents in excellent enantioselectivities (up to 98,% ee). An inversion in the sense of enantioselection was found between monophosphoric acid catalysts bearing different substituents introduced at the 3,3,-position of binaphthyl backbone. We also calculated the three-dimensional structure of the monophosphoric acid catalysts to speculate on the inversion of the stereochemical outcome. [source]


Improved Synthesis of Pyrroles and Indoles via Lewis Acid-Catalyzed Mukaiyama,Michael-Type Addition/Heterocyclization of Enolsilyl Derivatives on 1,2-Diaza-1,3-Butadienes.

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2007
Role of the Catalyst in the Reaction Mechanism
Abstract The Mukaiyama,Michael-type addition of various silyl ketene acetals or silyl enol ethers on some 1,2-diaza-1,3-butadienes proceeds at room temperature in the presence of catalytic amounts of Lewis acid affording by heterocyclization 1-aminopyrrol-2-ones and 1-aminopyrroles, respectively. 1-Aminoindoles have been also obtained by the same addition of 2-(trimethylsilyloxy)-1,3-cyclohexadiene on some 1,2-diaza-1,3-butadienes and subsequent aromatization. Mechanistic investigations indicate the coordination by Lewis acid of the enolsilyl derivative and its 1,4-addition on the azo-ene system of 1,2-diaza-1,3-butadienes. The migration of the silyl group from a hydrazonic to an amidic nitrogen, its acidic cleavage and the final internal heterocyclization give the final products. Based on NMR studies and ab initio calculations, a plausible explanation for the migration of the silyl protecting group is presented. [source]


Synthesis of N-Heteroaryl(trifluoromethyl)hydroxyalkanoic Acid Esters by Highly Efficient Solid Acid-Catalyzed Hydroxyalkylation of Indoles and Pyrroles with Activated Trifluoromethyl Ketones

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14 2005
Mohammed Abid
Abstract The synthesis of N-heteroaryl(trifluoromethyl)hydroxyalkanoic acid esters by solid acid-catalyzed Friedel,Crafts hydroxyalkylation of indoles and pyrroles with ethyl 3,3,3-trifluoropyruvate and ethyl 4,4,4-trifluoroacetoacetate is described. The inexpensive and readily available K-10 montmorillonite is found to be an efficient catalyst for the synthesis of a wide variety of trifluoromethylated indol-3-yl- and pyrrol-2-yl-hydroxypropionic and -butanoic acid esters. Using a series of substituted indoles and pyrroles the corresponding products were isolated in excellent yield (up to 98%) and 100% selectivity under mild experimental conditions, during very short reaction times. Beyond these, the ease of product isolation, catalyst stability and handling make this process an attractive, environmentally benign alternative for the synthesis of the target compounds. [source]


Silica Supported Sodium Hydrogen Sulfate and Amberlyst-15: Two Efficient Heterogeneous Catalysts for Facile Synthesis of Bis- and Tris(1H -indol-3-yl)methanes from Indoles and Carbonyl Compounds[1]

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 5 2003
Chimmani Ramesh
Abstract Bis- and tris(1H -indol-3-yl)methanes are synthesized in high yields by an electrophilic substitution reaction of indoles with carbonyl compounds under mild reaction conditions using two efficient heterogeneous catalysts, silica supported sodium hydrogen sulfate (NaHSO4,SiO2) and amberlyst-15. The second catalyst can be reused. [source]


Palladium-Catalyzed Ring-Expansion Reaction of Indoles with Alkynes: From Indoles to Tetrahydroquinoline Derivatives Under Mild Reaction Conditions,

ANGEWANDTE CHEMIE, Issue 24 2010
Zhuangzhi Shi
Ausbaufähiges Indol: Die hoch selektiv mit O2 als Oxidationsmittel und unter doppelter C-H-Aktivierung verlaufende Titelreaktion öffnet einen neuen Zugang zu polysubstituierten 4,5-Dihydrocyclopenta[c]chinolinen (siehe Schema). Außerdem wurden Einblicke in den Mechanismus dieser Ringerweiterung erhalten. [source]


Catalytic Oxyamidation of Indoles,

ANGEWANDTE CHEMIE, Issue 9 2010
Stéphane Beaumont Dr.
Zweifach variabel: Eine effiziente intermolekulare Oxyamidierung von Indolen beruht auf dem Einsatz von Rhodium(II)-katalysierten Nitren-Transfers. Durch Wechsel des Nucleophils kann die Reaktion selektiv zu den cis - oder trans -Produkten geführt werden. Auch die Regioselektivität der Addition kann gesteuert werden, indem man den Substituenten an der Indol-Doppelbindung variiert (siehe Schema). [source]


Concise One-Pot Tandem Synthesis of Indoles and Isoquinolines from Amides,

ANGEWANDTE CHEMIE, Issue 51 2009
Noriko Okamoto
Einfach zu Heterocyclen: Platin(II)-katalysierte Synthesen von Indolen und Isochinonen aus Isocyanaten , hergestellt mithilfe eines hypervalenten Iodreagens durch eine Amidumlagerung vom Hofmann-Typ , werden vorgestellt. Auch C2 -symmetrische makrocyclische Bis(indole) sind zugänglich, und zwar durch Transanellierung C2 -symmetrischer makrocyclischer Bis(alkincarbamat)-Zwischenstufen. [source]


Enantioselective Gold-Catalyzed Allylic Alkylation of Indoles with Alcohols: An Efficient Route to Functionalized Tetrahydrocarbazoles,

ANGEWANDTE CHEMIE, Issue 50 2009
Marco Bandini Dr.
Ein Tabu gebrochen: Die erste erfolgreiche direkte Verwendung von Allylalkoholen in katalytischen und enantioselektiven Friedel-Crafts-Alkylierungen gelang in Gegenwart chiraler Goldkomplexe. Diese intramolekulare Friedel-Crafts-Reaktion machte eine Vielzahl an funktionalisierten Tetrahydrocarbazolen zugänglich (siehe Schema; X=Me, F, Br, Cl, OMe; R=Me, Et, tBu; R,=H, Me). [source]


Iridium-Catalyzed Regio- and Enantioselective N-Allylation of Indoles,

ANGEWANDTE CHEMIE, Issue 42 2009

Iridium verschmäht C: Hoch regio- und enantioselektive iridiumkatalysierte N-Allylierungen von Indolen ergänzen üblichere Umsetzungen, in denen die Indole als Kohlenstoffnucleophile wirken (siehe Schema). Die Reaktionen führen zu stark enantiomerenangereicherten N -Allylindolen, aus denen sich leicht enantiomerenangereicherte 3-(1H -Indol-1-yl)- N -methyl-3-arylpropan-1-amine, Dihydropyrrolo[1,2- a]indole und (Indol-1-yl)propansäurederivate erhalten lassen. [source]


Asymmetric Construction of Polycyclic Indoles through Olefin Cross-Metathesis/Intramolecular Friedel,Crafts Alkylation under Sequential Catalysis,

ANGEWANDTE CHEMIE, Issue 40 2009
Quan Cai
Abgekürzt: Eine hocheffiziente Kaskadenreaktion (siehe Schema) liefert mit ausgezeichneter Enantioselektivität polycyclische Indole. Die Verknüpfung der beiden Stufen in einer sequentiellen Katalyse ermöglicht den Einsatz leichter zugänglicher Ausgangsmaterialien und macht die Synthese praktikabler. Boc=tert -Butoxycarbonyl. [source]


Palladium(II)-Catalyzed Regioselective Direct C2 Alkenylation of Indoles and Pyrroles Assisted by the N -(2-Pyridyl)sulfonyl Protecting Group,

ANGEWANDTE CHEMIE, Issue 35 2009
Alfonso García-Rubia
Leicht hin, leicht weg: In Gegenwart der N -(2-Pyridyl)sulfonylgruppe gelingt die direkte PdII -katalysierte Alkenylierung von Indolen an C2 in guten Ausbeuten (siehe Schema, DMA=Dimethylacetamid). Das Protokoll wurde auf Pyrrolderivate erweitert. Eine anschließende reduktive Desulfonylierung lieferte die C2-substituierten Indole und Pyrrole ebenfalls in guten Ausbeuten. [source]


Enantioselective, Thiourea-Catalyzed Intermolecular Addition of Indoles to Cyclic N -Acyl Iminium Ions,

ANGEWANDTE CHEMIE, Issue 34 2009
Emily
Freiwild für Indole sind N -Acyliminium-Ionen als Reaktionszwischenstufen, die unter der katalytischen Wirkung einer chiralen Thioharnstoff-Schiff-Base einer intermolekularen Addition dieser Nucleophile unterliegen. Die Methode wurde genutzt, um aus einfachen Vorstufen eine Vielfalt von funktionalisierten Indolgerüsten mit hoher Enantioselektivität aufzubauen (siehe Schema; TMS=Trimethylsilyl; R=H, Me, Vinyl, OMe, F, Cl, Br; R1=Benzyl, Methyl; n=1,2). [source]


Chemoselective Asymmetric N-Allylic Alkylation of Indoles with Morita,Baylis,Hillman Carbonates,

ANGEWANDTE CHEMIE, Issue 31 2009
Hai-Lei Cui
Einfach praktisch: Die Titelreaktion gelingt durch metallfreie Katalyse mit modifizierten Chinaalkaloiden. Mäßige bis ausgezeichnete Enantioselektivitäten wurden für eine Vielzahl an Substraten erreicht (siehe Schema). Die Reaktion bietet zudem einen bequemen Zugang zu mehrfach funktionalisierten Pyrrolo[1,2- a]indol- und Pyrrolo[3,2,1- ij]chinolinderivaten. [source]


ChemInform Abstract: Supported Cobalt Complex-Catalyzed Conjugate Addition of Indoles, Amines and Thiols to ,,,-Unsaturated Compounds.

CHEMINFORM, Issue 42 2010
Fatemeh Rajabi
Abstract A supported cobalt complex is successfully used as a reusable catalyst for the Michael addition of thiols (I), amines (VI), and indoles (VIII) to alkenes (II) and (IV) under solvent-free conditions. [source]


ChemInform Abstract: Hf(OTf)4 -Catalyzed Regioselective N-Aminomethylation of Indoles and Related NH-Containing Heterocycles.

CHEMINFORM, Issue 41 2010
Norio Sakai
Abstract Treatment of various N-heterocycles with N,O-acetals like (II) results in unusual, regioselective formation of N-aminomethylated products. [source]


ChemInform Abstract: The Michael Addition of Indoles and Pyrrole to ,-, ,-Unsaturated Ketones and Double-Conjugate 1,4-Addition of Indoles to Symmetric Enones Promoted by Pulverization-Activation Method and Thia-Michael Addition Catalyzed by Wet Cyanuric Chloride.

CHEMINFORM, Issue 36 2010
Ramin Ghorbani-Vaghei
Abstract The formation of cyanuric acid in wet cyanuric chloride catalyzes the solvent-free addition of indole, pyrrole, and thiols to ,,,-unsaturated ketones. [source]


ChemInform Abstract: Allylic Alkylation of Indoles with Butadiene Promoted by Palladium Catalyst and Triethylborane.

CHEMINFORM, Issue 34 2010
Masanari Kimura
Abstract The combination of Pd(0) catalyst and Et3B effectively activates butadiene (II) to undergo the C-allylation of indoles (I) via oligomerization of the diene (II). [source]


ChemInform Abstract: Dy(OTf)3/Pybox-Catalyzed Enantioselective Friedel,Crafts Alkylation of Indoles with ,,,-Unsaturated Trifluoromethyl Ketones.

CHEMINFORM, Issue 33 2010
Shigeru Sasaki
Abstract In most cases, good yields and enantioselectivities are obtained. [source]


ChemInform Abstract: Facile Creation of 3-Indolyl-3-hydroxy-2-oxindoles by an Organocatalytic Enantioselective Friedel,Crafts Reaction of Indoles with Isatins.

CHEMINFORM, Issue 33 2010
Jing Deng
No abstract is available for this article. [source]


ChemInform Abstract: Rhodium-Catalyzed [3 + 2] Annulation of Indoles.

CHEMINFORM, Issue 28 2010
Yajing Lian
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


ChemInform Abstract: Catalytic Oxyamidation of Indoles.

CHEMINFORM, Issue 27 2010
Stephane Beaumont
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]