CsF supported by α-alumina: An efficient basic catalyst

CsF supported by α- and γ-alumina was characterized by DTG-DTA coupled with mass spectral analysis of the gases evolved by the solid, XRD, ¹⁹F NMR spectroscopy, and tested in the Michael addition of cyclohexene-2-one with nitroalkanes and in the synthesis of alkyl carbonates. After dehydration at low temperature, ¹⁹F NMR spectroscopy shows that F is in part as CsF when the support is α-alumina but only as Cs ₃AlF₆ when the support is γ-alumina. CsF is detected by XRD on α-alumina but not on γ-alumina. On CsF/α-alumina the Michael condensation of 2-cyclohexen-1-one with nitroalkanes can be achieved in a few minutes with an equimolar mixture of reactants. Cs/α-alumina is also active after simple drying at 393 K, avoiding the usual activation at higher temperature. It is also surprisingly active for the transesterification of diethylcarbonate by different alcohols and diols with an activity nearly independent of the structure of the substrate.