From Homogeneous to Heterogeneous Catalysis: Novel Anchoring of Polypyrazolylborate Copper(I) Complexes on Silica Gel through Classical and Nonclassical Hydrogen Bonds. Use as Catalysts of the Oleum Cyclopropanation Reaction

1. Mar Díaz-Requejo, M.
2. Belderrain, T.R.
3. Nicasio, M.C.
4. Pérez, P.J.