Synthesis of Densely Functionalized 3a,4-Dihydro‑1H‑Pyrrolo[1,2‑b]Pyrazoles via Base Mediated Domino Reaction of Vinyl Malononitriles with 1,2-Diaza-1,3-dienes

A domino reaction of vinyl malononitriles (VMs) with 1,2-diaza-1,3-dienes (DDs) produce unprecedented 3a,4-dihydro-1H-pyrrolo[1,2-b]pyrazole systems in a chemo-, regio-, and stereoselective fashion. This base promoted (DIPEA) one-pot transformation involving multiple steps constructs one new C–C bond, two C–N bonds, and two new fused heterocyclic rings with total atom economy.