Hypervalent iodine‐mediated regioselective dearomatization of non‐activated arenes

The dearomatizations of non‐activated arenes, particularly those under mild reaction conditions, are highly desired transformations in organic synthesis due to their power in converting flat aromatic rings into three‐dimensional frameworks. Although hypervalent iodine (HVI)‐mediated dearomatization of phenol derivatives has developed rapidly, HVI‐mediated dearomatization of non‐activated arenes remains an urgent and challenging task. To fulfil this task, in this work, we established an HVI‐mediated oxidative dearomatization of non‐activated arenes by using biphenylureas and N‐ or O‐nucleophiles as reactants. This electrophilic dearomatization (DEAr) process is highly regioselective, which enabled different N‐ and O‐nucleophiles to react at the distal C4‐position of the phenyl ring, thus generating dearomative spiro‐products in a single step under mild conditions with wide substrate scope (43 examples, 22%−76% yield). This approach not only provides a successful example for dearomatization of non‐activated arenes under mild reaction conditions, but also has overcome the challenges in HVI‐mediated dearomatization of non‐activated arenes, which will enrich the chemistry of dearomatization.