Calix[n]arene sulfonic acids bearing pendant aliphatic chains as recyclable surfactant-type Brønsted acid catalysts for allylic alkylation with allyl alcohols in water

Calix[n]arene sulfonic acids bearing pendant aliphatic chains were developed as surfactant-type Brønsted acid catalysts for allylic alkylation with allyl alcohols in water. The allylic alkylation products of aromatic compounds were obtained in 60–94% yields. The water-solution of the surfactant-type catalyst was recovered by means of simple extraction of water-insoluble products and centrifiguation, which can be reused in the next cycle directly. After recycling seven times, the catalytic activity for the aqueous reaction still remained at a high level (92–96% yields).