Stereoselective Synthesis of β-Amino Acid Derivatives by Asymmetric Mannich Reaction in Flow

Abstract

Abstract A continuous flow synthesis of β-amino acid derivatives has been demonstrated using an asymmetric Mannich reaction. An enolate of tert-butyl acetate was successfully prepared in 10 s at room temperature in a flow reactor, and the desired β-amino acid derivatives were stereoselectively obtained within a short residence time (40 s) in moderate-to-good yields. Sequential N-alkylation of the Mannich product in the flow reactor was also achieved in the presence of DMPU that provided N-alkylated β-amino acid derivatives in good yields.