Catalytic oxidations of alcohols - Advances in Catalytic Activation of Dioxygen by Metal Complexes - page 138

discussed above the method suffers from the drawback that one equivalent of
a carboxylic acid is formed as a coproduct.

4. PALLADIUM-CATALYZED OXIDATIONS WITH

Palladium(II) is also capable of mediating the oxidation of alcohols via
the hydridometal pathway shown in Figure 1. Blackburn and Schwarz first
reported 57 the aerobic oxidation of alcohols in
1977. However, activities were very low, with turnover frequencies of the
order of 1 Subsequently, much effort has been devoted to finding
synthetically useful methods for the palladium-catalyzed aerobic oxidation
of alcohols. For example, the giant palladium cluster,
was shown to catalyze the aerobic oxidation of primary allylic alcohols to
the corresponding

aldehydes (Reaction 14) 59 .

in combination with as a base in DMSO as solvent
catalyzed the aerobic oxidation of primary and secondary allylic and
benzylic alcohols to the corresponding aldehydes and ketones, respectively,
in fairly good yields 60 . Similarly, in combination with sodium
carbonate and a tetraalkylammonium salt, Adogen 464, as a phase transfer
catalyst, catalyzed the aerobic oxidation of alcohols, e.g. 1,4- and 1,5-diols
afforded the corresponding lactones (Reaction 15) 61,62 .