Chemistry Letters, Vol.37, No.4, 436-437, 2008
Electronically modified polymer-supported cinchona phase-transfer catalysts for asymmetric synthesis of alpha-alkyl-alpha-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.