annulation between 2-aminobiphenyls and activated olefins is disclosed for succinct synthesis of valuable phenanthridine scaffolds. The protocol avails a common organic functional group, free amine, as a directing group and represents a unique combination of C–Hactivation/annulation/C–C bond cleavage cascade that bodes well in the production of bioactive alkaloids including trisphaeridine and bicolorine
Reactions of organic azides. Part III. The synthesis of phenanthridines by the interaction of fluoren-9-ols with hydrazoic and sulphuric acids, and the mechanism of the rearrangement of the intermediate azides