LAUSR

Supramolecular catalysis has become a hot topic in chemistry. To understand the origin of supramolecular catalysis, the catalytic mechanism of a synthetic cavitand receptor with an inwardly directed carboxylic acid for ring-opening cyclization of epoxy alcohols was investigated by performing density functional theory (DFT) calculations. The results reveal that the epoxy alcohol can be ring-opened via backside attack of the hydroxyl group to the epoxy group and cyclized in 5-exo and 6-endo modes. The carboxylic acid can catalyze the ring-opening cyclization of the epoxy alcohol through organocatalysis, since the carboxyl group can easily provide a proton to protonate the epoxy group. The synthetic cavitand receptor with an inwardly directed carboxylic acid can further catalyze the ring-opening cyclization of an epoxy alcohol through organocatalysis and supramolecular catalysis as a result of the hydrogen-bonding and C–H···π interactions formed between the receptor and substrate. Furthermore, the special st...