I2/K2S2O8‐Catalyzed Cascade Synthesis of Insecticidal 2‐Imino‐1,3‐Thiazoles: A Sustainable Approach to Bioactive Heterocycles

This study introduces a catalytic strategy for the synthesis of 2‐iminothiazoles and their selenidazole/oxazole analogues via a cascade process. By utilizing iodine catalysis and K₂S₂O₈ as an oxidant under mild conditions, the method shows a wide substrate scope, allowing the integration of sulfur, selenium, or oxygen into heterocyclic frameworks. Mechanistic studies propose a pathway involving nucleophilic addition of thioureas to enaminones, leading to a‐sulfur functionalized intermediates and subsequent intramolecular cyclization. Notably, the synthesized compounds exhibit insecticidal activity against Plutella xylostella larvae, with compound 3o displaying an LC50 of 1.759 mg/L. This versatile methodology offers a sustainable approach for constructing bioactive heterocycles as potential insecticidal lead compounds.