A general and efficient one-pot aminoethylation of substituted indoles/pyrroles was accomplished for the synthesis of various tryptamine derivatives employing a combination of alkynes and sulfonyl azides as readily accessible aminoethylating agents. The reaction features a successful integration of copper-catalyzed alkyne and azide cycloaddition to N-sulfonyl-1,2,3-triazole, rhodium-catalyzed selective insertion of α-iminocarbenes onto the C3-H bond of indoles, and reduction of the resultant enamides to tryptamine derivatives employing either NaCNBH3 or palladium catalyst, in one-pot. The reaction also showed excellent functional-group tolerance and allowed the synthesis of various substituted tryptamines in good to excellent yield. This transformation constitutes a one-pot formal regioselective functionalization of terminal alkynes. Utility of the synthesized tryptamine was further demonstrated in the synthesis of dihydro-β-carboline and tryptoline. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pazhamalai Anbarasan

Department Of Chemistry

Shanmugam Rajasekar

catalysis

CATALYSTS

Nitrogen compounds

Rhodium

Synthesis (chemical)

AMINOETHYLATION

Indoles

Palladium catalyst

REGIOSELECTIVE FUNCTIONALIZATION

SUBSTITUTED INDOLES

Triazoles

TRYPTAMINE DERIVATIVES

TRYPTAMINES

Hydrocarbons

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Chemistry - A European Journal

An efficient proline-catalyzed synthesis of 4,5-disubstituted-N-sulfonyl-1,2,3-triazoles has been accomplished from 1,3-dicarbonyl compounds and sulfonyl azides. The developed reaction is suitable for various symmetrical and unsymmetrical 1,3-dicarbonyl compounds, tolerates various functional groups and affords 4,5-disubstituted-N-sulfonyl-1,2,3-triazoles in good yield with excellent regioselectivity. Rhodium-catalyzed denitrogenative functionalization of 4,5-disubstituted-N-sulfonyl-1,2,3-triazoles further demonstrates their utility in organic synthesis. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Chemistry - An Asian Journal

A General Proline-Catalyzed Synthesis of 4,5-Disubstituted N-Sulfonyl-1,2,3-Triazoles from 1,3-Dicarbonyl Compounds and Sulfonyl Azide

An efficient and novel rhodium-catalyzed transannulation of N-sulfonyl-1,2,3-triazoles with in situ generated o-quinone methides (o-QMs) from 2-hydroxybenzyl alcohols has been achieved for the synthesis of substituted benzopyrans in good yields. The developed reaction involves nucleophilic attack of o-QM to α-imino rhodium carbenoid to generate a carbonyl ylide followed by 6π-electrocyclization and isomerization. Furthermore, the utility of the methodology was demonstrated in the one-pot synthesis and construction of polyheteroaromatics. Copyright © 2018 American Chemical Society.

Organic Letters

Rhodium Catalyzed Synthesis of Benzopyrans via Transannulation of N-Sulfonyl-1,2,3-triazoles with 2-Hydroxybenzyl Alcohols

An efficient diastereoselective rhodium catalyzed synthesis of indolines possessing two contiguous tetrasubstituted carbon centers has been achieved with good to excellent yields using ortho-vinylanilines and iminocarbenes derived from N-sulfonyl-1,2,3-triazoles. The reaction affords excellent cis-diastereoselectivity through the initial formation of a N-ylide followed by intramolecular trapping with unactivated alkenes via an ene-type reaction with a well-organized transition state, namely intramolecular carbenylative amination of alkenes. The developed transformation was further extended to the successful synthesis of tricyclic compounds, imidazoindolines, through reduction and hypervalent iodine mediated oxidative cyclization. © 2016 The Royal Society of Chemistry.

Fulltext

Chemical Science

Rhodium catalyzed diastereoselective synthesis of 2,2,3,3-tetrasubstituted indolines from: N -sulfonyl-1,2,3-triazoles and ortho -vinylanilines

Rhodium catalyzed synthesis of substituted tetrahydropyridines was accomplished from readily accessible thio-tethered N-sulfonyl-1,2,3-triazoles. The reaction involves tandem rhodium catalyzed 1,2-sulfur migration in β-thio-α-diazoimines, generated from thio-tethered N-sulfonyl-1,2,3-triazoles, to thio-substituted 1-azadiene and subsequent self aza-Diels-Alder reaction. Interestingly, the methodology was effectively extended to the synthesis of fused tetrahydropyridines, dihydropyridines and cyclohexenes through the in situ trapping of the intermediate, 1-azadiene, with various dienophiles such as enol ether, enamine, ketene S,S-acetal, alkyne, alkene and diene. Furthermore, the direct conversion of propargyl sulfides to (fused)-tetrahydropyridines was also achieved through the successful integration of copper and rhodium catalysts in one-pot. © 2015 The Royal Society of Chemistry.

Tandem 1,2-sulfur migration and (aza)-Diels-Alder reaction of β-thio-α-diazoimines: Rhodium catalyzed synthesis of (fused)-polyhydropyridines, and cyclohexenes

An efficient rhodium catalyzed direct arylation of α-diazoimines, generated from readily accessible 1,2,3-triazole, has been accomplished for the synthesis of 2,2-diaryl enamides. The reaction involves the chemo- and regioselective insertion of rhodium azavinyl carbene into aromatic C(sp 2)-H bonds. Utility of the developed methodology was demonstrated in the synthesis of indole and tetrahydroisoquinoline frameworks. © 2014 American Chemical Society.

Rhodium catalyzed direct arylation of α-diazoimines

Suitably substituted electron-deficient 1,2,3-triazoles exist in equilibrium with their ring-opened α-diazoimine tautomers. This phenomenon was used to facilitate the generation of synthetically useful metallo azavinyl carbene intermediates. In this short review, we describe recent developments in the transition-metal-catalyzed decomposition of electron-deficient (annulated) 1,2,3-triazoles to form metallo azavinyl carbenes, and their application in the synthesis of highly functionalized nitrogen-based heterocycles and building blocks through various synthetic transformations, such as transannulation, cyclopropanations, insertion reactions, ylide formation/rearrangements, and ring expansions. 1 Introduction 2 Ring-Chain Isomerism 3 Synthesis of N-Sulfonyl-1,2,3-triazoles 4 Denitrogenative Transformations of 1,2,3-Triazoles 4.1 Transannulations with Nitriles and Alkynes 4.2 Transannulations with Alkenes or Carbonyl Compounds 4.3 Transannulations with (Hetero)cumulenes or 1,3-Dienes 4.4 Insertions into X-H or C-X bonds 4.5 Rearrangement/Ring Expansion 4.6 Miscellaneous Transformations 5 Summary and Outlook. © Georg Thieme Verlag Stuttgart - New York.

Synthesis (Germany)

Recent advances in transition-metal-catalyzed denitrogenative transformationsÂ- of 1,2,3-triazoles and related compounds

Chemical building blocks: α-Sulfenylated imines containing a quaternary center, an ubiquitous subunit and excellent building block, were achieved by rhodium-catalyzed denitrogenative [2,3] sigmatropic rearrangements of N-sulfonyl-1,2,3-triazoles with allylaryl(alkyl) sulfides. Coupling of this methodology with a copper-catalyzed cycloaddition reaction provides a platform for the direct regioselective functionalization of alkynes (see scheme; TC=thiophenecarboxylate; Ts=p-toluenesulfonyl). © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Journal	Data powered by TypesetChemistry - A European Journal
Publisher	Data powered by TypesetWiley-VCH Verlag
ISSN	09476539
Open Access	No