Dithiocarbamates: Reagents for the Removal of Transition Metals from Organic Reaction Media

Dithiocarbamates (DTCs) are ligands known to chelate with Cu and other transition metals to form insoluble complexes. Wastewater treatment protocols have utilized DTCs to remove trace (ppb) metals from waste streams. We have extended the applicability of DTCs to a protocol that readily enables control of the residual Cu in isolated material in a quick and cost-effective manner. Formation of the chelate complex typically results in purging of Cu and a variety of other metals in an array of reaction media to <= 10 ppm. Furthermore, the simplicity of the method makes it very attractive for large-scale applications late in a synthetic sequence because of the low toxicity and efficient removal of the metal complex by filtration.