Designing and Accurately Developing a [6 + 2] Dipolar Cycloaddition for the Synthesis of Benzodiazocines

1,6-Dipolar
cycloadditions represent a valuable strategy for the
rapid construction of medium-sized rings. Herein, we describe the
concept for the design of 1,6-dipoles that bypasses the regioselectivity.
Through the introduction of an amino group into Morita–Baylis–Hillman
(MBH) carbonates, unprecedented [6 + 2] dipolar cycloadditions were
accurately developed with Cs2CO3, efficiently
delivering a series of benzodiazocines in mild conditions. Computational
studies bring a deeper understanding of this reaction.