Ozonolysis Goes With The Flow

Chemists have designed a method to turn the highly useful and environmentally friendly ozonolysis of alkenes into a flow reaction. It’s a safer alternative to traditional batch methods, which risk explosions from shock-sensitive peroxy intermediates and require large reaction volumes. Ozonolysis also avoids the use of metal catalysts, such as the toxic osmium tetraoxide often used in alkene oxidations (Org. Lett., DOI: 10.1021/ol100322t). Steven V. Ley and colleagues of the University of Cambridge developed the proof-of-principle process using a chamber containing semipermeable fluorinated copolymer tubing (Teflon AF-2400). An alkene substrate flowing through the tubing in the ozone-filled chamber interacts with ozone at a steady pace as the gas diffuses through the tubing. The researchers tested the flow reaction on a variety of alkenes, such as 1,1-diphenylethene, which was converted to benzophenone. They envision using the flow method for other types of reactions that involve diffusing gases or liquids and extending the design to the manufacture of microfluidic devices with variable temperature and pressure control.