Cyclodimerization of α-methylstyrene under homogeneous and heterogeneous acid catalysis conditions

The cyclodimerization of α-methylstyrene in the presence of Brönsted and Lewis acids was realized. The dependence of the cyclic α-methylstyrene dimer yield on the catalyst nature and structure was established. It was shown that the activity of the catalysts is determined by the strength of their acid sites, and the selectivity for the cyclic α-methylstyrene dimer depends on the nature of the anion (homogeneous acids) or the porous structure (heterogeneous catalysts). Sulfuric acid and silicophosphate exhibit the highest selectivity in the cyclodimerization of α-methylstyrene into 1,1,3-trimethyl-3-phenylindane.