Dithiane-Induced [3+2] Cycloaddition Tactic for the Convergent Synthesis of Dihydropyrrole and Pyrrole Derivatives.

An efficient transition-metal-free tactic for the convergent synthesis of substituted dihydropyrroles and pyrroles by β-chloro-vinyl dithiane cyclization with a broad range of imines was developed. [3+2] Cyclization and aromatization occur under these reaction conditions providing biologically relevant dihydropyrroles and pyrroles in good yields.