Et3N catalyzed cascade reaction of Meldrum’s acid with ortho-hydroxyaryl aldehydes for the synthesis of coumarin-3-carboxylic acids under solvent-less condition

Synthesis and in vitro antimicrobial activity evaluation of coumarin-3-carboxylic acids obtained via cascade reaction using chitosan as a recyclable catalyst

“…This methodology provided results superior to those achieved by various methods related in the literature as sustainable and eco-friendly using homogeneous catalysts and water as solvent. 13,17,29,30 However, when using monosubstituted salicylaldehyde derivatives containing bulky groups (entry 8, Table 4) or disubstituted (entry 9, Table 4), the reactions proceeded slowly. In this case, their reaction showed low yields, likely due to the low solubility of these substrates in water.…”