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

A new protocol to prepare 2-aryl-3-(arylselanyl)imidazo[1,2-a]pyridines under blue light irradiation, using benzeneseleninic acid derivatives as selenium source, is described. The experimental design approach (DoE) was used to establish the best reaction conditions, which delivered fourteen derivatives in moderate to good yields (23%–75%) using water as solvent at room temperature.

Abstract

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.

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