Synthesis of β-triazolylenones via metal-free desulfonylative alkylation of N-tosyl-1,2,3-triazoles

Soumyaranjan Pati; Renata G Almeida; Eufrânio N da Silva Júnior; Irishi N N Namboothiri

doi:10.3762/bjoc.17.66

Synthesis of β-triazolylenones via metal-free desulfonylative alkylation of N-tosyl-1,2,3-triazoles

Beilstein J Org Chem. 2021 Mar 31:17:762-770. doi: 10.3762/bjoc.17.66. eCollection 2021.

Authors

Soumyaranjan Pati¹, Renata G Almeida², Eufrânio N da Silva Júnior², Irishi N N Namboothiri¹

Affiliations

¹ Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, 400 076, India.
² Institute of Exact Sciences, Department of Chemistry, Federal University of Minas Gerais, CEP 31270-901, Belo Horizonte, MG, Brazil.

Abstract

Desulfonylative alkylation of N-tosyl-1,2,3-triazoles under metal-free conditions leading to β-triazolylenones is reported here. The present study encompasses the synthesis of triazoles with a new substitution pattern in a single step from cyclic 1,3-dicarbonyl compounds and N-tosyl triazole in moderate to high yields. Our synthesis takes place with complete regioselectivity as confirmed by crystallographic analysis which is rationalized by a suitable mechanistic proposal. This method provides an efficient, versatile and straightforward strategy towards the synthesis of new functionalized 1,2,3-triazoles.

Keywords: 1,2,3-triazoles; azoles; cycloaddition; enones; heterocycles.

Grants and funding

ENSJ thanks CNPq, CAPES, Return Fellowship of the Alexander von Humboldt Foundation (AvH) and the Royal Society of Chemistry for the research fund grant (R19-9781). INNN thanks SERB, India for financial support. SP thanks CSIR, India for a senior research fellowship.