Polymer-Supported Cinchona Alkaloid-Derived Ammonium Salts as Recoverable Phase-Transfer Catalysts for the Asymmetric Synthesis of α-Amino Acids
Open Access
Abstract
Alkaloids such as cinchonidine, quinine and N-methylephedrine have been N-alkylated using polymeric benzyl halides or co-polymerized and then N-alkylated, thus affording a series of polymer-supported chiral ammonium salts which have been employed as phase-transfer catalysts in the asymmetric benzylation of an N-(diphenylmethylene)glycine ester. These new polymeric catalysts can be easily recovered by simple filtration after the reaction and reused. The best ee’s were achieved when Merrifield resin-anchored cinchonidinium ammonium salts were employed.Keywords
This publication has 45 references indexed in Scilit:
- Polymer-Supported Organic CatalystsChemical Reviews, 2003
- Solution- and Solid-Phase Approaches in Asymmetric Phase-Transfer Catalysis by Cinchona Alkaloid DerivativesSynthesis, 2001
- Asymmetric PTC C-Alkylation Catalyzed by Chiral Derivatives of Tartaric Acid and Aminophenols. Synthesis of (R)- and (S)-α-Methyl Amino AcidsThe Journal of Organic Chemistry, 2000
- Carbon−Carbon Bond Forming Solid-Phase ReactionsChemical Reviews, 1999
- Heterogeneous asymmetric aminohydroxylation of alkenes using a silica gel-supported bis-cinchona alkaloidChemical Communications, 1998
- Soluble Polymer-Bound Ligand-Accelerated Catalysis: Asymmetric DihydroxylationJournal of the American Chemical Society, 1996
- Functionalization of crosslinked polystyrene resins: 2. Preparation of nucleophilic resins containing hydroxyl or thiol functionalitiesPolymer, 1979
- Functional polymers. 1. Poly(cinchona alkaloid-co-acrylonitrile)s. New polymer catalysts for asymmetric synthesisJournal of the American Chemical Society, 1978
- Polymergebundene Cinchonaalkaloide als Katalysatoren in der Michael ReaktionHelvetica Chimica Acta, 1977
- Stereo-ordered macromolecular matrices bearing ammonium groups as catalysts in alkylation and carbenation reactionsJournal of the Chemical Society, Chemical Communications, 1977