Benzeneseleninic acid (BSA) derivatives were used as an alternative, but extremely useful, source of Se(II)-based electrophiles, generated in situ by thermal decomposition, to construct C–Se bonds, accessing 3-selanylimidazopyridines after reaction with 2-substituted imidazopyridines. A total of thirty-four derivatives were synthesized in 50–94% yield, seventeen of which were so far unprecedented. A simple and efficient protocol is described, just delivering H₂O and diaryl diselenide as by-products. Diaryl diselenides can be easily recovered during the purification process and converted again to BSA for a new reaction.

Here, we describe a magnetic resonance spectroscopy characterization of selenium cyanide compounds, Se(CN)₂, Se₂(CN)₂ and Se₃(CN)₂. Selenim-77 and carbon-13 nuclides were used to provide data of these species at room temperature. This is the first structural characterization performed using NMR for Se₃(CN)₂, while only low-temperature analyses have been conducted so far for Se(CN)₂ and Se₂(CN)₂. Based on these limitations, a characterization study was deemed mandatory, especially from a synthetic chemistry point of view. In addition to these analyses, we carried out a purity assessment for Se₃(CN)₂ according to the melting point parameter along with a solubility evaluation.

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 H ₂ O and diaryl diselenide as byproducts, which can be recovered and reused.