NHC-catalysed [3 + 2]-asymmetric annulation between pyrazolin-4,5-diones and enals: Synthesis of novel spirocyclic pyrazolone γ-butyrolactones and computational study of mechanism and stereoselectivity

1. Gil-Ordóñez, M.
2. Maestro, A.
3. Ortega, P.
4. Jambrina, P.G.
5. Andrés, J.M.