Isoquinolinium N ‐arylimides and strained cycloalkenes

In contrast to common alkenes and enol ethers, the angle‐strained double bonds of norbornene, dimethyl norbornadiene‐2,3‐dicarboxylate, and acenaphthylene undergo [3+2] cycloadditions with isoquinolinium N ‐arylimides. The structures of the crystalline adducts have been elucidated from their 1 H nmr spectra.