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.

Pazhamalai Anbarasan

Department Of Chemistry

Building blockes

CHEMICAL BUILDING BLOCKS

Cycloaddition Reaction

QUATERNARY CENTERS

REGIOSELECTIVE FUNCTIONALIZATION

Rhodium-catalyzed

Sigmatropic rearrangements

SULFENYLATED IMINES

Copper

Cycloaddition

Nitrogen compounds

Rhodium

catalysis

Sulfur

article

chemistry

protein quaternary structure

Sigmatropic rearrangement

Protein Structure, Quaternary

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IIT Madras

Chemistry - A European Journal

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.

Fulltext

Chemical Science

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

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.

One-Pot Aminoethylation of Indoles/Pyrroles with Alkynes and Sulfonyl Azides

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

Reference Module in Chemistry, Molecular Sciences and Chemical Engineering

Cambridge Crystallographic Data Centre (CCDC)

Journal of the American Chemical Society

Application of In Situ-Generated Rh-Bound Trimethylenemethane Variants to the Synthesis of 3,4-Fused Pyrroles

Synthesis of Enaminones by Rhodium-Catalyzed Denitrogenative Rearrangement of 1-(N-Sulfonyl-1,2,3-triazol-4-yl)alkanols

Angewandte Chemie International Edition

Transition-Metal-Catalyzed Denitrogenative Transannulation: Converting Triazoles into Other Heterocyclic Systems

Accounts of Chemical Research

Stereoselective Construction of Quaternary Carbon Stereocenters via a Semipinacol Rearrangement Strategy

Rhodium-catalyzed denitrogenative [2,3] sigmatropic rearrangement: An efficient entry to sulfur-containing quaternary centers

Journal	Chemistry - A European Journal
ISSN	09476539
Open Access	No