Highly functionalized 1-azafluorenones were obtained from indeno[2,1-a]isoindolones through Ag2O-mediated cascade reaction. The cascade process includes the oxidation of vicinal alcohol and dihydropyridine to generate a pyridinium intermediate which is trapped in situ by a nucleophile. Functional groups such as methoxy, thiomethyl and aldehyde survived the Ag2O treatment whereas the dimethylamino group was partially demethylated.
![Graphical abstract: Ag2O mediated N-demethylation and oxidative opening of indenopyrido[2,1-a]isoindolones. Efficient access to polysubstituted 1-azafluorenones](http://hg.y866.cn/compound/lib/scimg/usr/1/C3RA43278E.jpg)
