Mechanisms of Brønsted Acid Catalyzed Additions of Phenols and Protected Amines to Olefins: A DFT Study
DFT calculations at the B3LYP/6-31G(d) level were performed to understand the mechanism of the recently developed trifluoromethanesulfonic acid (TfOH) catalyzed intermolecular additions of phenols and protected amines to simple olefins. A novel mechanism involving a concerted, eight-membered-ring transition structure for the addition of the alcohol/amine to the alkene with TfOH as a catalyst was located. In the addition transition structure, the alkene sub