Applications of Oxidation and Hydrogenation

Hydrogenation and oxidation certainly constitute two areas where transition metal catalysis has brought the most impressive contributions. As these fields cannot be treated in detail within the frame of the present chapter, only a few selected applications will be reported as illustrations of their tremendous potentialities and general interest (both on the huge industrial scale as well as in the synthesis of elaborate molecules). 

The Wacker reaction is an important process at the industrial level but several applications of related reactions have been reported in natural products synthesis. 

Oxidation of phenols. Copper catalyzed oxidation of phenols, notably of pyrocatechol, has been extensively studied as a biomimetic model, muconic acid being formed. 

More useful from the preparative point of view, are the palladium catalyzed oxidations which proceed either by addition of hydroxyl groups to double bonds when an olefin is present (a) (telomerization can even occur with butadiene), or by formation of quinoid systems (b)  

Epoxidations. Vanadium based catalysts are largely used for olefin epoxidation by hydroperoxides (such as butyl hydroperoxide). These catalysts are very regioselective for epoxidation of double bonds of allylic alcohols [56]. 

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