Cascade Reaction of Morita-Baylis-Hillman Acetates with 1,1-Enediamines or Heterocyclic Ketene Aminals: Synthesis of Highly Functionalized 2-Aminopyrroles.

A new strategy for the construction of two kinds of fully substituted pyrroles, including 2-aminopyrroles and bicyclic pyrroles from Morita-Baylis-Hillman (MBH) acetates with 1,1-enediamines (EDAMs), or heterocyclic ketene aminals (HKAs) via base-promoted tandem Michael addition, elimination, and aromatization sequence has been developed, affording the expected products in moderate to excellent yields. This methodology is a highly efficient, concise way to access 2-aminopyrroles or bicyclic pyrroles with diversity in molecular structures from accessible building blocks under moderate reaction conditions.