Brønsted Acid or Lewis Acid Catalyzed [3+3] Cycloaddition of Azomethine Imines with N-Benzyl Azomethine Ylide: A Facile Access to Bicyclic N-Heterocycles.

1,3-Dipolar cycloaddition reactions are one of the most important methods to obtain diverse heterocycles with novel skeletons. We herein report the Brønsted acid or Lewis acid catalyzed [3+3] cycloaddition of azomethine imines with nonstabilized azomethine ylide generated in situ from an N-benzyl precursor, providing a clean and facile access to diverse bicyclic N-heterocycles in moderate to good yields for further biological testing. Also, the protocol developed achieved the formation of C-C and C-N bonds simultaneously in a single step. [ABSTRACT FROM AUTHOR]