Molybdenum‐Catalyzed Deoxygenation of Heteroaromatic N‐ Oxides and Hydroxides using Pinacol as Reducing Agent

A molybdenum‐catalyzed deoxygenation of pyridine N ‐oxides and N ‐hydroxybenzotriazoles, as well as other azole N ‐oxides, has been developed using pinacol as an environmentally friendly oxo‐acceptor. The only by‐products are acetone and water making the process a convenient alternative to established protocols in terms of waste generation. The reaction is highly chemoselective and a variety of functional groups are tolerated. The processes are usually very clean allowing the isolation of the pure deoxygenated products after a simple extraction in most cases.