Enantioselective 1,3-Dipolar Cycloaddition of Cyclic Enones Catalyzed by Multifunctional Primary Amines: Beneficial Effects of Hydrogen Bonding

摘要

Organocatalytic asymmetric reactions provide an environmentally benign approach to a variety of optically pure compounds. In particular, the development of organocata-lysts bearing two or more activating functionalities has provoked increasing attention, because a concerted interaction among multifunctional catalyst and reactants can generally lead to more efficient catalysis and enantiocontrol. Most bifunctional organocatalysts combine a Br0nsted acid and Lewis base in one molecule to activate an electrophile and nucleophile, respectively. However, this strategy has not been applied to organocatalytic cycloaddition reactions.