Solvent-free aerobic epoxidation of dec-1-ene using gold/graphite as a catalyst
The oxidation of dec-1-ene has been investigated using gold nanoparticles supported on graphite in the presence of a radical initiator (α,α-azobisisobutyronitrile) using oxygen from air as oxidant. We have investigated the influence of the reaction temperature (70-100 °C), catalyst mass and reaction time on the epoxide yield. In the absence of a radical initiator the reaction does not proceed, although auto-oxidation can occur at higher temperatures in the range studied. However, in the presence of an initiator, selective oxidation occurs and the initiator propagates the reaction through the formation of a peroxy-radical at the allylic C3 position. Graphite enhances the formation of the allylic products dec-1-en-3-ol, dec-1-en-3-one, and dec-2-en-1-ol; however, the addition of gold nanoparticles to the graphite, enhances formation of 1,2-epoxydecane. It is suggested that gold suppresses the formation of allylic products via a Russell termination.