Spiro thiochromene–oxindoles as novel anti-inflammatory agents: design, sustainable synthesis, in vitro and in silico evaluations

(4h). Bioactivity and pharmacokinetic parameters were further analyzed, encompassing ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) characteristics. This study highlights the potential of spiro thiochromene-oxindoles as anti-inflammatory agents, warranting further exploration as potential leads. The synthetic strategy for these target compounds utilizes taurine as an eco-friendly bio-organic catalyst, facilitating an acid-, base-, and metal-free intramolecular C-S and C-C bond formation in aqueous media. The reaction involves a one-pot, three-component Knoevenagel-Thia-Michael cascade between substituted isatins, 1,3-dicarbonyls, and 2-naphthalene thiol. Key features of this green protocol include high yields, cost-efficiency, non-toxicity, atom economy, and acid-, base-, and metal-free synthesis in water. Additionally, the catalyst exhibits excellent reusability, maintaining its activity across three cycles with easy recovery, while product isolation is achieved through simple filtration, eliminating the need for chromatographic purification and organic solvents. These attributes underscore this approach's synthetic and environmental advantages, highlighting its potential for broader application in the development of anti-inflammatory agents.