Imidazo[1,2-a]pyridine A3-Coupling Catalyzed by a Cu/SiO2 Material

Helena de Salles, Tiago da Silva, Cátia Radatz, Ricardo Affeldt, Edilson Benvenutti, Paulo Schneider
2019 Journal of the Brazilian Chemical Society  
In this work, we report the preparation of a copper-silica material (Cu/SiO 2 ) by a sol-gel methodology and its characterization concerning composition and textural properties. The Cu/SiO 2 material was successfully applied as a Lewis acid heterogeneous catalyst for the A 3 -coupling from 2-aminopyridine, aldehydes and alkynes to imidazo[1,2-a]pyridines (45-82%), which are relevant pharmacological scaffolds. The synthesis shows a number of advantages, such as easy separation from the reaction
more » ... from the reaction media and the minimal formation of metal aqueous wastes. Investigation of the mechanism supports the involvement of the formation of reaction intermediates inside the pores of the mesoporous material prior to 5-exo-dig cyclization.
doi:10.21577/0103-5053.20190089 fatcat:jxt6amolj5bsjnptsszzx267zy