Isocyanide Purification: C-2 Silica Cleans Up a Dirty Little Secret

EtSiCl 3 -treated silica gel, ‘C-2 silica,’ proved exceptionally effective for purifying isocyanides that are otherwise irreversibly adsorbed during silica gel chromatography. Purification of a prototypical isocyanide on several chromatographic matrices provided valuable insight into the requirements for purifying silica-sensitive isocyanides. EtSiCl 3 -modified silica proved optimal as the solid phase, providing up to 90% recovery of pure isocyanides that otherwise fail to elute during silica gel purification.