Catalytic oxidations of alcohols - Advances in Catalytic Activation of Dioxygen by Metal Complexes - page 142

Compared to existing systems for the aerobic oxidation of alcohols the
Pd-bathophenanthroline system is at least an order of magnitude more
reactive, requires no solvent and product/catalyst isolation involves simple
phase separation. The system has broad scope but is not successful with all
alcohols. Some examples of unreactive alcohols are shown in Figure 10.
Low reactivity was generally observed with alcohols containing functional
groups which could strongly coordinate to the palladium.
The reaction is half-order in palladium and first order in the alcohol
substrate, when measured with a water soluble alcohol to eliminate the
complication of mass transfer. A possible mechanism is illustrated in Figure
11. The resting catalyst is a dimeric complex containing bridging hydroxyl