Highly efficient heterogeneous acylations of aromatic compounds with acid anhydrides and carboxylic acids by montmorillonite-enwrapped titanium as a solid acid catalyst

Abstract

Montmorillonite-enwrapped titanium hydroxide species (Ti4+-mont) acted as a highly efficient heterogeneous acid catalyst for the acylation of aromatic compounds with acid anhydrides or carboxylic acids. The catalytic activity of the Ti4+-mont was higher than those of other acid catalysts such as zeolites, SO42−/ZrO2 and p-toluenesulfonic acid. For example, the reaction of anisole with dodecanoic acid in the presence of the Ti4+-mont catalyst gave 1-(4-methoxyphenyl)-1-dodecanone in 97% yield. Furthermore, the Ti4+-mont catalyst was easily separated from the reaction mixture and was recyclable.