Light-Mediated Decomposition of Arylseleninic Acids in Aqueous Medium: A Green Alternative Toward Organoselenium-Functionalized Imidazo[1,2-a]pyridines

In the present work, a mild protocol was developed to construct 2-aryl-3-(arylselanyl)imidazo[1,2-a]pyridines, under blue light irradiation, employing benzeneseleninic acid derivatives as a Se(II) source. The experimental design approach (design of experiment, DoE) was used to establish the best reaction conditions, which delivered fourteen derivatives in moderate to good yields (23%–75%), after reacting for 24–48 h. Furthermore, the developed method proved to be efficient when increasing the reaction scale (2.5 mmol), which provided the desired product in 70% yield (0.61 g) after 24 h of reaction, demonstrating the applicability of this method on a preparative scale. The present approach does not require the use of metals, strong oxidants, or heating, in addition to producing only H₂O and diaryl diselenide as byproducts, which can be recovered and reused.