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.

Pazhamalai Anbarasan

Department Of Chemistry

Angula Chandra Shekar Reddy

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

Organic Letters

An efficient cascade Rh(ii) and Yb(iii) catalyzed transannulation of N-sulfonyl-1,2,3-triazoles with β-naphthols has been accomplished for the synthesis of substituted naphthofurans in good yields. The reaction involves the initial rhodium catalyzed insertion of azavinyl carbene into the O-H bond followed by ytterbium catalyzed annulative C-C bond formation and concomitant aerial oxidation. The developed reaction was successfully extended to phenols to afford substituted benzofurans. Furthermore, the synthetic utility of the method was demonstrated through the synthesis of important polyhetero aromatic compounds. © 2019 The Royal Society of Chemistry.

Chemical Communications

Cascade Rh(ii) and Yb(iii) catalyzed synthesis of substituted naphthofurans: Via transannulation of N -sulfonyl-1,2,3-triazoles with β-naphthols

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.

Chemistry - A European Journal

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

Rhodium-catalyzed transannulation of N-sulfonyl-1,2,3-triazoles with vinyl ether has been accomplished for the synthesis of various polysubstituted pyrroles. The present method allows the synthesis of mono-, di-, and trisubstituted pyrroles with appropriate substitutions. Furthermore, the developed methodology was applied in the formal synthesis of neolamellarin A, an antitumor agent. © 2014 American Chemical Society.

Journal	Data powered by TypesetOrganic Letters
Publisher	Data powered by TypesetAmerican Chemical Society
ISSN	15237060
Open Access	No