Alkylation of arenes with benzylic and propargylic alcohols -: Classical versus fancy catalysts

Gold chloride and BF3 (.) etherate were tested as Friedel-Crafts catalysts in the propargylation of electron-rich arenes: differences in reactivity of the catalysts can be used to achieve high selectivity either for monoalkylation or for multiple alkylation products. In the case of a macrocyclization towards a heterocalixarene, gold catalysts exhibited a pronounced selectivity, whereas p-toluenesulfonic acid as catalyst opened up a competing pathway to a structural isomer.