Pragmatic Access\nto Hybrid Quinoxaline Scaffold Mediated\nby Elemental Sulfur Enabling Actualization to π‑Extended\nand Aza-Annulated Heterocyclic Units

A metal-free approach for synthesizing hybrid quinoxaline\nderivatives\nfrom sulfoxonium ylide and a 1,5-bis-nucleophilic N-heterocycle mediated\nby elemental sulfur is presented to illuminate the [5+1] cascade cyclization\nsequence. Large-scale synthesis and postsynthetic functionalizations\nfor the annulative π-extension and intramolecular aza-annulation\nreactions reveal the potential utility and actualize the fabricated\napproach.