Access to 8-Azabicyclo[3,2,1]octanes via the [3 + 2] Cycloaddition of Oxidopyridinium Ions to Maleimides.

Herein, we reported a unique and operationally simple method to assemble 8-azabicyclo[3,2,1]octanes by using oxidopyridinium ions and maleimides as synthons. The features of good to high yields and good functional group tolerance are achieved regularly under mild conditions. Of note, oxidopyridinium ions undergo a [3 + 2] cycloaddition on their C2 and C6 positions.