Solvatochromic fluorescent 2-substituted 3-ethynyl quinoxalines: four-component synthesis, photophysical properties, and electronic structure.

2-Substituted 3-ethynylquinoxalines can be rapidly synthesized in generally excellent yields by a consecutive four-component synthesis starting from electron-rich π-nucleophiles, oxalyl chloride, terminal alkynes, and 1,2-diaminoarenes. The title compounds are highly fluorescent with a pronounced emission solvatochromism. The photophysical properties and electronic structure were additionally corroborated by computations on the DFT level of theory.