Electronically Modified Polymer-supported Cinchona Phase-transfer Catalysts for Asymmetric Synthesis of α-Alkyl-α-amino Acid Derivatives.

Merrifield resin-supported hydrocinchonidinium salts containing particular functional groups that can participate in hydrogen bonding were prepared and evaluated as chiral phase-transfer catalysts using the asymmetric benzylation of glycine imine ester. These electronically modified Merrifield resin-supported phase-transfer catalysts generally provided better enantioselectivities compared to the unmodified ones. [ABSTRACT FROM AUTHOR]