Iodine mediated in situ generation of R-Se–I: application towards the construction of pyrano[4,3-b]quinoline heterocycles and fluorescence properties

Abstract

In this paper, we report the iodine mediated in situ generation of R-Se–I and further its application towards the construction of pyrano[4,3-b]quinolin-1-one derivatives. The structural elaboration of 1-chloro-8-methyl-3-phenylbenzo[b][1,6]naphthyridine 6 was successfully achieved by Sonogashira, Suzuki coupling and dehalogenation reactions. Finally, the synthesized compounds 4a, 5a, 5b, 6, and 7a–7c were studied for photophysical properties including UV-absorption, fluorescence, and quantum yield studies. The synthesized pyranoquinoline derivatives showed λ_max, F_max and Φ_f values in the range of 391–447 nm, 436–486 nm and 0.004–0.301, respectively in chloroform solvent.