Copper-Catalyzed [5 + 1] Cyclization of -Pyrrolo Anilines and Heterocyclic -Tosylhydrazones for Access to Spiro-dihydropyrrolo[1,2-]quinoxaline Derivatives.

An inexpensive copper-catalyzed sequential reaction process, proceeding via a nucleophilic attack of amine to Cu-carbene generated in situ from heterocyclic -tosylhydrazone precursors followed by a 1,2-H shift/oxidative cyclization cascade of -ylides, has been described, smoothly generating the corresponding structurally various spiro-dihydropyrrolo[1,2-]quinoxaline derivatives. Furthermore, the significance of this protocol can be also highlighted by its diverse conversions of the synthetic compounds to the potentially bioactive molecules such as the 2-substituted pyrrolo[1,2-]quinoxalins.