Superelectrophilic-initiated carbon cationic relay reactions of diazafluorenones with phenols were developed to provide strategically novel and atom-economic access to spirodiazafluorenes via tandem Friedel-Crafts reaction, nucleophilic addition, and intramolecular cyclization sequences. A range of spirodiazafluorenes that are difficult to synthesize with traditional protocols has been constructed successfully in middle to high yields using this method.