title: Regioselective, Solvent- and Metal-Free Chalcogenation of Imidazo[1,2-a]pyridines by Employing I2 /DMSO as the Catalytic Oxidation System.
abstract: Highly efficient molecular-iodine-catalyzed chalcogenations (S and Se) of imidazo[1,2-a]pyridines were achieved by using diorganoyl dichalcogenides under solvent-free conditions. This approach afforded the desired products that had been chalcogenated regioselectively at the C3 position in up to 96 % yield by using DMSO as an oxidant, in the absence of a metal catalyst, and under an inert atmosphere. This mild, green approach allowed the preparation of different types of chalcogenated imidazo[1,2-a]pyridines with structural diversity. Furthermore, the current protocol was also extended to other N-heterocyclic cores.
authors.affiliation: Departamento de Química, Universidade Federal de Santa Catarina, Florianopolis, 88040-900, Brazil.
authors.forename: Jamal
authors.identifier: http://orcid.org/0000-0002-2336-040X
authors.initials: J
authors.lastname: Rafique
authors.affiliation: Departamento de Química, Universidade Federal de Santa Catarina, Florianopolis, 88040-900, Brazil.
authors.forename: Sumbal
authors.identifier: http://orcid.org/0000-0002-6134-7249
authors.initials: S
authors.lastname: Saba
authors.affiliation: Departamento de Química, Universidade Federal de Santa Catarina, Florianopolis, 88040-900, Brazil.
authors.forename: Alisson R
authors.identifier: http://orcid.org/0000-0001-9713-2189
authors.initials: AR
authors.lastname: Rosário
authors.affiliation: Departamento de Química, Universidade Federal de Santa Catarina, Florianopolis, 88040-900, Brazil. braga.antonio@ufsc.br.
authors.forename: Antonio L
authors.identifier: http://orcid.org/0000-0001-9903-6764
authors.initials: AL
authors.lastname: Braga
keywords: green chemistry; iodine; nitrogen heterocycles; selenium; sulfur