[8+2]‐Cycloaddition Reaction of Carbamates and N‐Sulfonyl azaheptafulvenes

The base‐mediated higher‐order [8+2]‐cycloaddition reaction of carbamates with N‐sulfonyl azaheptafulvenes has been successfully developed, providing a facile access to a series of highly functionalized cycloheptatriene‐fused imidazolidin‐2‐one derivatives in 52–95 % yields. This reaction features transition‐metal free, simple operation, and mild reaction conditions. Additionally, this transformation can also be utilized to modify some natural isolates. Herein, we disclose a base‐mediated formal [8+2]‐cycloaddition reaction of N‐sulfonyl azaheptafulvenes with carbamates under mild reaction conditions, which provides a facile access to structurally diverse cycloheptatriene‐fused imidazolidin‐2‐ones with moderate to excellent yields (52–95 %). In addition, this method could be applied to modify some natural isolates.