Catalysts can influence stereochemistry through several mechanisms:
Chiral Catalysts: These catalysts themselves are chiral and can induce chirality in the products. Common examples include chiral phosphine ligands used in asymmetric hydrogenation. Chiral Induction: Achieved through the use of chiral auxiliaries or chiral solvents that interact with a substrate to produce a chiral product. Template-Based Catalysis: A chiral template can organize the substrate in a specific spatial arrangement, leading to stereoselective reactions.
