Pyrazolo-fused 4-azafluorenones as key reagents for the synthesis of fluorescent dicyanovinylidene-substituted derivatives

Jessica Orrego‐HernándezCarolina LizarazoJusto CoboJaime Portilla2026-03-222026-03-22201910.1039/c9ra04682hhttps://doi.org/10.1039/c9ra04682hhttps://andeanlibrary.org/handle/123456789/44990Citaciones: 36A green process to access pyrazolo-fused 4-azafluorenones (indeno[1,2-b]pyrazolo[4,3-e]pyridines, IPP) 4a-xvia the three-component reaction between indan-1,3-dione (1), benzaldehydes 2 and 5-amino-1-arylpyrazoles 3 is described. These compounds were successfully used as precursors of the novel dicyanovinylidene derivatives 7a-d containing different acceptor (A) or donor (D) aryl groups at position 4 of its fused system. The structures of products obtained (4a-x and 7a-d) were determined based on NMR experiments, HRMS analysis, and X-ray diffraction studies for 7b. The photophysical and computational studies of 7a-d showed that these products are modulable ICT fluorophores, even some preliminary tests revealed that these compounds could be used as fluorescent chemodosimeters for cyanide detection.enReagentFluorescenceKey (lock)Combinatorial chemistryChemistryPyrazolo-fused 4-azafluorenones as key reagents for the synthesis of fluorescent dicyanovinylidene-substituted derivativesarticle