Photoswitchable Chiral Phase Transfer Catalyst

Azo-crown ether-based photoswitching chiral phase transfer catalysts have been developed to control the catalytic activity by photoirradiation. Azobenzene binaphthyl crown ether (ABCE) can switch its reactivity and selectivity through structural transformation of the crown ether moiety induced by E/Z photoisomerization of azobenzene. (Z)-ABCE promoted enantioselective alkylation of the glycine Schiff base to afford chiral amino acid derivatives in good yields with high enantiomer ratios. In contrast, (E)-ABCE hindered the reaction progress under the same conditions.

Automated summary

The Azo-crown ether-based photoswitching chiral phase transfer catalysts control catalytic activity through structural transformation induced by E/Z photoisomerization. This allows for promotion or hindrance of the enantioselective alkylation of glycine Schiff base to yield chiral amino acid derivatives.