Ligand-free Pd/Ag-mediated dehydrogenative alkynylation of imidazole derivatives

Fabio Bellina; Matteo Biagetti; Sara Guariento; Marco Lessi; Mattia Fausti; Paolo Ronchi; Elisabetta Rosadoni

doi:10.1039/d1ra05303e

Ligand-free Pd/Ag-mediated dehydrogenative alkynylation of imidazole derivatives

RSC Adv. 2021 Jul 22;11(41):25504-25509. doi: 10.1039/d1ra05303e. eCollection 2021 Jul 19.

Authors

Fabio Bellina¹, Matteo Biagetti², Sara Guariento², Marco Lessi¹, Mattia Fausti¹, Paolo Ronchi², Elisabetta Rosadoni¹

Affiliations

¹ Dipartimento di Chimica e Chimica Industriale, Università di Pisa Via Moruzzi 13 56124 Pisa Italy fabio.bellina@unipi.it.
² Chemistry Research and Drug Design, Chiesi Farmaceutici S.p.A., Centro Ricerche Largo Belloli 11/A 43122 Parma Italy.

Abstract

A variety of 2-alkynyl(benzo)imidazoles have been synthesized by dehydrogenative alkynylation of (benzo)imidazoles with terminal alkyne in NMP under air in the presence of Ag₂CO₃ as the oxidant and Pd(OAc)₂ as the catalyst precursor. The data obtained in this study support a reaction mechanism involving a non-concerted metalation deprotonation (n-CMD) pathway.