Enantioselective Addition of Amines to Ketenes Catalyzed by a Planar-Chiral Derivative of PPY: Possible Intervention of Chiral Brønsted-Acid Catalysis
摘要:
The first method for the catalytic enantioselective addition of amines (specifically, pyrroles) to ketenes has been developed, and it has been demonstrated that the resulting acylpyrroles can be transformed into a broad spectrum of useful derivatives. On the basis of mechanistic studies, it is suggested that the planar-chiral catalyst plays an unanticipated role in this process as a chiral Brønsted acid.