Catalytic asymmetric synthesis of either enantiomer of physostigmine. Formation of quaternary carbon centers with high enantioselection by intramolecular Heck reactions of (Z)-2-butenanilides
摘要:
A practical method for preparing either enantiomer of physostigmine and congeners is reported. The Z stereochemistry of the butenanilide cyclization substrate is required to obtain high enantioselection (95% ee) in the key asymmetric Heck insertion.