Supported gold nanoparticles for aerobic, solventless oxidation of allylic alcohols

After giving some general considerations about the specific properties of nanoparticles below 20 nm, procedures for size stabilization, and the importance of developing green alcohol oxidation reactions, catalytic data are presented showing that gold nanoparticles (3-7 nm) supported on nanoparticulated ceria (4 nm) are far more chemoselective than related palladium catalysts for the aerobic oxidation of allylic alcohols. Using palladium catalysts, in addition to minor oxidation of the alcohol functional group, we have also observed polymerization, 1-2 hydrogen shift, and hydrogenation. In contrast, ceria-supported gold nanoparticles exhibit a remarkable chemoselectivity (in many cases, almost complete) to the alcohol oxidation.