One-pot synthesis of (2-furanylmethylene)malononitrile, a Knoevenagel product of furfural with malononitrile, from xylose efficiently proceeded by combined use of acid Amberlyst-15 and acid-base Cr/hydrotalcites in 44% yield.
Preparation of inorganic–organic composites as acid–base catalysts using HCa2Nb3−xTaxO10 and quaternary onium salts