Synthesis Via Electrospray

Electrospray—a mainstay of mass spectrometrists in which an electric field is used to disperse a solution into a fine mist of charged droplets—might also find a place in synthetic chemists’ tool kits, according to a report (Angew. Chem. Int. Ed., DOI: 10.1002/anie.201206632). Compartmentalized liquids such as micelles and emulsions are often used to enhance chemical reactions. Thomas Müller of the University of Innsbruck, in Austria, along with Abraham Badu-Tawiah and R. Graham Cooks of Purdue University wondered whether the charged micro­droplets generated with electrospray might serve the same purpose. The chemists studied the base-catalyzed Claisen-Schmidt condensation of 1-indanone and 4-chlorobenz­aldehyde. They conducted the reaction in a flask at room temperature, as well as in an electrospray apparatus equipped with four multiplexed electrosonic spray ionization tips. Whereas the benchtop reaction took several hours to complete, the electrospray method generated products in better than 90% yield within the time of flight of the evaporating charged droplets. The technique, the researchers note, could be used to make milli­gram quantities of material in a matter of minutes.