General and Selective C‐3 Alkylation of Indoles with Primary Alcohols by a Reusable Pt Nanocluster Catalyst

Siddiki, S. M. A. Hakim; Kon, Kenichi; Shimizu, Ken‐ichi

doi:10.1002/chem.201302464

Cited by 61 publications

(44 citation statements)

References 30 publications

(42 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…On the other hand, reacting indole 1 a with preformed imine 8 and replacing benzoquinone by hydroquinone led to full conversion and product 3 a was isolated in 42 % yield. These results demonstrated that benzoquinone acted as a hydrogen shuttle in the overall process, which appears to proceed by a hydrogen‐borrowing mechanism analogous to the known metal‐based protocols 6a,b. 9…”

Section: Methodsmentioning

confidence: 77%

“…using Shvo’s ruthenium catalyst 6a. The analogous process using benzyl and aliphatic alcohols has also been described employing catalytic Pt nanoclusters6b and stoichiometric hydroxide base 6c. These high‐temperature reactions (140–150 °C for 24 h) are initiated by dehydrogenation of the amine or alcohol to give an imine or aldehyde electrophile 5 , followed by nucleophilic addition–elimination of indoles 1 furnishing a putative 1‐azadiene intermediate 6 .…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Tandem Organocatalysis and Photocatalysis: An Anthraquinone‐Catalyzed Indole‐C3‐Alkylation/Photooxidation/1,2‐Shift Sequence

2014

View full text Add to dashboard Cite

Quinones exhibit orthogonal ground- and excited-state reactivities and are therefore highly suitable organocatalysts for the development of sequential catalytic processes. Herein, the discovery of an anthraquinone-catalyzed thermal indole-C3-alkylation with benzylamines is described, which can be combined sequentially with a new visible-light-driven catalytic photooxidation/1,2-shift reaction. The one-flask tandem process converts indoles into 3-benzylindole intermediates, which are further transformed into new fluorescent 2,2-disubstituted indoline-3-one derivatives.

show abstract

Section: Methodsmentioning

confidence: 77%

Section: Methodsmentioning

confidence: 99%

Tandem Organocatalysis and Photocatalysis: An Anthraquinone‐Catalyzed Indole‐C3‐Alkylation/Photooxidation/1,2‐Shift Sequence

2014

View full text Add to dashboard Cite

show abstract

“…With regard to the base, LiOtBu, KOtBu, and Cs 2 CO 3 were found to be equally effective for this transformation (see Table S1, Supporting Information). A decrease in temperature or the amount of base led to unreacted indole, with inferior yield of the desired product (entries [12][13][14]. Omission of the catalyst or base resulted in no desired product formation (entries 15-16).…”

Section: Iridium-catalyzed Methylation Of Indoles and Pyrroles Using mentioning

confidence: 99%

Iridium-catalyzed methylation of indoles and pyrroles using methanol as feedstock

Chen

Cai

2015

RSC Adv.

View full text Add to dashboard Cite

COMMUNICATIONThis journal is www.rsc.org/ hydride suspended the "hydrogen-returning" process, so the Michael addition became dominated. Our idea for producing 3-methylindole was to interrupt the Michael addition by accelerating the consumption of indole and the reduction of the intermediate A.According to this train of thoughts, increasing the loading of the catalyst, which promoted the formation of metal hydride with the concomitant release of formaldehyde, was a possible way to achieve this goal.

show abstract

“…(27)]. Hier ist keine Base notwendig, weil θ‐Al 2 O 3 die Aldolkondensation des Indols mit dem in situ erzeugten Aldehydintermediat erleichtert.…”

Section: Heterogene üBergangsmetallkatalysierte C‐alkylierung Von Keunclassified

C‐Alkylierung von Ketonen und verwandten Verbindungen durch Alkohole: übergangsmetallkatalysierte Dehydrierung

Huang

Liu

2015

Angewandte Chemie

View full text Add to dashboard Cite

Die übergangsmetallkatalysierte C‐Alkylierung von Ketonen und sekundären Alkoholen mit Alkoholen umgeht den Einsatz von metallorganischen oder umweltschädlichen Alkylierungsreagentien über die Borrowing‐Hydrogen(BH)‐ oder Hydrogen‐Autotransfer(HA)‐Aktivierung der Alkoholsubstrate. Da Wasser als einziges Begleitprodukt entsteht, ist das BH‐Verfahren atomökonomisch und umweltfreundlich. Viele homogene und heterogene Übergangsmetallkatalysatoren, Ketone und Alkohole sind in dieser Reaktion einsetzbar, sodass das BH‐Verfahren aussichtsreich scheint, die derzeitigen Verfahren zu ersetzen, die herkömmliche Alkylierungsreagentien verwenden. Dieser Kurzaufsatz fasst die Fortschritte in der übergangsmetallkatalysierten α‐Alkylierung von Ketonen und β‐Alkylierung von sekundären Alkoholen mit Alkoholen mithilfe der BH‐Technik während der letzten fünf Jahre zusammen. Auch die Eignung der BH‐Strategie zur C‐C‐Bindungsbildung wird diskutiert.

show abstract

General and Selective C‐3 Alkylation of Indoles with Primary Alcohols by a Reusable Pt Nanocluster Catalyst

Abstract: The platinum rule: Heterogeneous, additive-free C-3 selective alkylation of indoles by aliphatic and aromatic alcohols proceeded under transfer hydrogenation conditions with the reusable Pt/θ-Al2 O3 catalyst (see scheme; TON=turnover number).

Cited by 61 publications

References 30 publications

Tandem Organocatalysis and Photocatalysis: An Anthraquinone‐Catalyzed Indole‐C3‐Alkylation/Photooxidation/1,2‐Shift Sequence

Tandem Organocatalysis and Photocatalysis: An Anthraquinone‐Catalyzed Indole‐C3‐Alkylation/Photooxidation/1,2‐Shift Sequence

Iridium-catalyzed methylation of indoles and pyrroles using methanol as feedstock

C‐Alkylierung von Ketonen und verwandten Verbindungen durch Alkohole: übergangsmetallkatalysierte Dehydrierung

Contact Info

Product

Resources

About