2008

200834.fm Seite 80 Donnerstag, 24. Juli 2008 9:46 09

Aminocarboxylic acids (hydrazinocarboxylic acids) and estersQ 0440 Electronically Modified Polymer-Supported Cinchona Phase-Transfer Catalysts

for Asymmetric Synthesis of α-Alkyl-α-amino Acid Derivatives. — Merrifield res-in supported hydrocinchonidinium salts, e.g. (I) and (II), containing particular function-al groups that can participate in hydrogen bonding are evaluated as chiral phase-transfer catalysts using the asymmetric benzylation of glycine imine ester (I) as a model reac-tion. These electronically modified catalysts generally provide better enantioselectivity compared to the unmodified ones. — (SHI, Q.; LEE, Y.-J.; SONG, H.; CHENG, M.; JEW, S.-S.; PARK*, H.-G.; JEONG, B.-S.; Chem. Lett. 37 (2008) 4, 436-437; Res. Inst. Pharm. Sci., Coll. Pharm., Seoul Natl. Univ., Kwanak, Seoul 151-742, S. Korea; Eng.) — M. Paetzel

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