Elucidation of Regioselectivity and Stereoselectivity in the Isatin-Aminorhodanine Hybrids Synthesis

A regio- and stereoselective synthesis of a novel isatin–aminorhodanine hybrid heterocycle, a potential kinase inhibitor, was achieved through the condensation of 3-aminorhodanine with isatin in the presence of acetic acid as a catalyst. Although the reaction could theoretically yield three isomers, only one product was obtained. Theoretical analysis combining Conceptual Density Functional Theory (CDFT) and thermodynamic data revealed that acetic acid facilitates the enolization of aminorhodanine, which directs the regio- and stereoselectivity toward the exclusive formation of the observed isomer.