Herein, we report the [Bis(trifluoroacetoxy)iodo]benzene mediated C−H bond arylselenylation of 4H‐Pyrido‐[1,2‐a]‐Pyrimidin‐4‐ones using readily available organodiselenides. This methodology is scalable and permits for the generation of a broad spectrum of functionally and structurally diverse selenoether derivatives in very promising yields (up to 98%). Notably, this protocol proceeds at ambient conditions and in the absence of a metal. The application of this methodology for the facile synthesis of ArSe substituted 5H‐thiazolo‐pyrido[3,2‐a]pyrimidin‐4‐ones is also demonstrated.

An operationally simple C–SCN and C–SeCN bond formation technique to generate different SCN/SeCN substituted 4-quinolone derivatives using NH4SCN/KSeCN in excellent yields was developed.

An operationally simple sodium iodide-mediated C–S and C–Se bond formation protocol involving substituted 4-quinolone and thiols/diselenide to generate different ArS/ArSe-substituted 4-quinolone derivatives in excellent yields was developed. The versatility of this methodology has been successfully demonstrated by extension of the suitable reaction conditions to both substrates having different substituents. This regioselective C–H bond activation approach provides a direct access of structurally diverse 3-sulfenylated/selenylated 4-quinolone derivatives. Moreover, this new method proceeds without a transition-metal catalyst and prerequisite NH protection of 4-quinolone derivatives.

We have discovered an unprecedented metal-free route for the direct C-3 chalcogenation of various 4H-pyrido[1,2-a]pyrimidin-4-ones under mild conditions in good to excellent yields.

A novel and eco‐friendly technique for the synthesis of C‐3 nitro derivatives of 4‐quinolones via the regioselective C(sp2)−H bond functionalization employing tert‐butyl nitrite as nitrating agent in presence of TEMPO [(2,2,6,6‐tetramethylpiperidin‐1‐yl)oxyl] as an oxidant is unfolded herein. The protocol is scalable as well as high yielding with wide substrate scope and broad functional group tolerance. In‐depth mechanistic investigations revealed that the reaction occurred through a free radical pathway. The nitro derivatives of 4‐quinlones were selectively reduced to corresponding aminated 4‐quinolones. Finally, the photophysical properties of synthesized amine derivatives were also investigated, and some of them showed good fluorescence properties.