Oxidative Spirocyclization of Aromatic Substrates

The oxidative dearomatization of appropriately substituted phenolic substrates resulting in intramolecular cyclization with the formation of spirocyclic products represents one of the most powerful synthetic tools in modern organic synthesis (Seetion 3.1.11). Kita and coworkers were the first to report a catalytic variant of the oxidative spirocyclization reaction based on the in situ regeneration of a [bis(trifluoroacetoxy)iodo]arene from iodoarene using mCPBA as a terminal oxidant [2]. In a representative example, the oxidation of 

4-MeC6H4l(OCOCF3)2 (0.01 equiv.), mCPBA (1.5 equiv) CF3CO2H (50 equiv), CH2CI2, rt, 2 h 

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