Highly practical amino acid and alkaloid synthesis using designer chiral phase transfer catalysts as high-performance organocatalysts.

A series of chiral quaternary ammonium salts derived from commercially available (R)- or (S)-binaphthol have been designed as new C(2)-symmetric chiral phase transfer catalysts. In order to realize the flexible design of these phase transfer catalysts, the combinatorial design approach has been developed. These chiral high-performance organocatalysts have been successfully applied to the highly practical asymmetric synthesis of various amino acid derivatives including α-alkyl and α,α-dialkyl-α-amino acids in addition to alkaloids.