(R,R)-3,4,5-Trifluorophenyl-NAS Bromide

[Green Chemistry]Chiral Phase-Transfer Catalysts(PTC)

Chiral phase-transfer catalysts, which are optically active spiro ammonium salts with 2 binaphthyl rings that allow for easy molecule designing, were invented by Professor Maruoka of the Kyoto University.(R,R)-3,4,5-Trifluorophenyl-NAS Bromide shows high catalytic activity and high enantioselectivity in asymmetric alkylation of alpha-amino acid derivatives1⁾.By using (R,R)-3,5-Bistrifluoromethylphenyl-NAS Bromide, beta-hydroxy alpha-amino acid derivatives which are important chiral units of biologically active peptides are obtained in good yield by the aldol reaction of glycine derivatives with aldehydes. It was found that erythro isomers, which are major products, were obtained with high enantioselectivity²⁾.

[Features]

1. The rational molecular design of C₂-symmetric chiral quaternary ammonium salt
2. Reaction under mild organic / aqueous biphase conditions
3. Catalyzing the asymmetric alkylations of alpha-amino acid derivatives and the direct asymmetric aldol reactions of glycine schiff base with aldehydes to the corresponding beta-hydroxy-alpha-amino acid derivatives

1. Ooi T., Takeuchi M., Kameda M. and Maruoka K. : J. Am. Chem. Soc., 122 (21), 5228-5229 (2000).
2. Ooi T., Taniguchi M., Kameda M., Maruoka K. : Angew. Chem. Int.