Synthesis of Spironitrodihydroacridines via Formal [5 + 1] Spiroannulation and Nitroso Group Oxidative Migration.

Presented herein is a cascade reaction featuring multiple-C-H bond activation-initiated formal [5 + 1] spiroannulation along with simultaneous nitroso group oxidative migration of N-nitrosodiarylamine with a diazo compound. Based on this reaction, a novel method for the synthesis of spironitrodihydroacridine derivatives was developed. This protocol has advantages such as simple starting materials, multiple reaction steps accomplished in one pot, high atom economy, an unprecedented reaction mechanism, and ready scalability. Moreover, the products thus obtained possess powerful anticancer activity and tunable fluorescence, endowing them with the ability to self-track their action mechanisms in living systems.