Calix[6]arene derivatives bearing sulfonate and alkyl groups as surfactants in Sc(OTf)3-catalyzed Mukaiyama aldol reactions in water

Amphiphilic calix[6]arene derivatives 1a–b were found to be efficient surfactants for Sc(OTf)3-catalyzed Mukaiyama aldol reaction of silyl enol ethers with aldehydes in water. The results indicated that a hydrophobic microenvironment was formed in the reaction system, which is favorable to stabilize some labile silyl enol ethers and thus promotes the reactions.