Josep Comelles, Marcial Moreno-Mañas, Elisabet Pérez, Anna Roglans, Rosa M. Sebastián, and Adelina Vallribera. Ionic and Covalent Copper(II)-Based Catalysts for Michael Additions. The Mechanism. J. Org. Chem. 2004, 69 (20): 6834–6842. doi:10.1021/jo049373z.
Takeshi Uemura and Naoto Chatani. Copper Salt Catalyzed Addition of Arylboronic Acids to Azodicarboxylates. J. Org. Chem. 2005, 70 (21): 8631–8634. doi:10.1021/jo051387x.
Vijay Nair, Smitha C. Mathew, Akkattu T. Biju, and Eringathodi Suresh. A Novel Reaction of the 'Huisgen Zwitterion' with Chalcones and Dienones: An Efficient Strategy for the Synthesis of Pyrazoline and Pyrazolopyridazine Derivatives. Angew. Chem. Int. Ed. 2007, 46: 2070 –2073. doi:10.1002/anie.200604025.