Enantioselective Thiourea-Catalyzed Cationic Polycyclizations

摘要

Advances in cyclase enzymology have provided strong evidence that cation-π interactions play an essential catalytic role in biosynthetic polyene cyclizations. Structural, kinetic, and site-directed mutagenesis studies all suggest that the cationic intermediates and transition states accessed in these transformations are stabilized through a series of attractive interactions with aromatic residues that line the cyclase active site. This mechanistic insight suggests the intriguing possibility that analogous stabilizing cation-π interactions might also be engineered into selective small-molecule catalysts.