Enantioselective Catalytic Synthesis of ?-Halogenated ?-Aryl-? 2,2- amino Acid Derivatives

The enantioselective synthesis of a broad variety of novel differently functionalized alpha-halogenated alpha-aryl-beta 2,2-amino acid derivatives by means of an ammonium-salt-catalyzed asymmetric alpha-halogenation of isoxazolidin-5-ones was accomplished. Key to success to obtain high levels of enantioselectivities was the use of Maruoka's spirocyclic binaphthyl-based ammonium salts, and detailed accompanying mechanistic studies using density functional theory methods revealed the key features for the catalyst-substrate interactions.

Automated summary

The enantioselective synthesis of novel differently functionalized alpha-halogenated alpha-aryl-beta 2,2-amino acid derivatives was achieved using an ammonium-salt-catalyzed asymmetric alpha-halogenation of isoxazolidin-5-ones. The use of Maruoka's spirocyclic binaphthyl-based ammonium salts and detailed mechanistic studies revealed the key features for the catalyst-substrate interactions.