Highly efficient synthesis of 9-aminoxanthenes via the tandem reaction of arynes with salicyl N-tosylimines

A cascade insertion–nucleophilic annulation reaction of salicyl N-tosylimines with aryne generated in situ from 2-(trimethylsilyl) aryl triflate and KF-18-crown-6 has been developed, providing 9-aminoxanthenes efficiently in one step.