Removal of Heavy Metals from Organic Reaction Mixtures: Preparation and Application of Functionalized Resins
journal contributionposted on 20.11.2009, 00:00 by Damien Barbaras, Jörg Brozio, Ib Johannsen, Thomas Allmendinger
Using a toolbox, sulfur and amine ligands are attached to a variety of hydrophobic and hydrophilic resins, and the combinations were tested for the removal of heavy metals from a number of products, prepared by metal-catalyzed reactions. As a result, cheap combinations of silica resins and simple polyamines proved to be among the most effective metal scavengers particularly in apolar solvents such as cyclohexane. Expensive cyclic polyamines are not suitable, owing to kinetic retardation of complexation. Functionalized PEG-based polymers, originally designed for solid phase synthesis, show promising performance as metal scavengers. The results are discussed and compared to alternative approaches for purification such as salt-formation and chemical downstream transformation.