Asymmetric Brønsted Acid Catalysis Enabling Hydroaminations of Dienes and Allenes

Acid treatment: Toste et al. recently unveiled a new pathway for asymmetric Brønsted acid catalysis of reactions involving dienes or allenes, and achieved highly efficient intramolecular hydroamination and hydroarylation reactions (see scheme). The PS bond proved necessary for reactivity, and dithiophosphoric acids emerged as efficient catalysts. The association/displacement sequence led to chiral pyrrolidines and isoxazolidines in excellent yields and ee values.