Catalytic Conversions in Water. Part 23: Steric Effects and Increased Substrate Scope in the Palladium-Neocuproine Catalyzed Aerobic Oxidation of Alcohols in Aqueous Solvents

Article abstract of DOI:10.1002/adsc.200303134

The steric influence of substituents on the 2-and 9-positions of phenanthroline in the (2,9-R₂-1,10-phenanthroline)palladium(II)- catalyzed aerobic oxidation of 2-hexanol was investigated by means of high throughput experimentation. (Neocuproine)Pd-(OAc)₂ (R=CH ₃) was found to be a highly active catalyst for alcohol oxidation in 1:1 water/DMSO mixtures. The catalyst is unique in that it tolerates water, polar co-solvents and a wide variety of functional groups in the alcohol. Turn-over frequencies of > 1500 h^-1 were achieved and a series of alcohols was oxidised with 0.1 to 0.5 mol % of catalyst.