Organometallic Complexes as Catalysts in Oxidation of C—H Compounds

Department of Kinetics and Catalysis, Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia 

In various C-H oxygenation reactions, organometallic complexes can play the role of precatalyst. Compounds bearing carbon-metal bonds can also be some of intermediate compounds in the catalytic cycles. In this chapter, we discuss reactions in which an organometallic complex catalyzes the insertion of oxygen atoms into C-H bonds of hydrocarbons or other organic compounds. The focus will be made on the author s own works. 

2 OXYGENATION REACTIONS WITH OXIDANTS OTHER THAN PEROXIDES 

The first example of a metal-catalyzed oxygen atom insertion into the C-H bond was the reaction found by Shilov and Shteinman and their coworkers in 1972 (for reviews, see References Ih and 5). These authors demonstrated that Pt Cl4 ion could catalyze H/D exchange in methane in a D2O/CD3COOD solution and, if Pt Cls is added, the latter oxidizes methane to methanol (Shilov chemistry). The catalytic cycle in which ct-methyl complexes of platinum(ll) and platinum(lV) are involved is shown in Fig. 1.1. 

Periana and coworkers proposed (2,2 -bipyrimidyl)platinum(ll)dichloride as a catalyst ( Periana system see a recent review [4d]). Fuming sulfuric acid is the oxidant in this case. A simplified scheme of the catalytic cycle is shown in Fig. 1.2. It can be seen that some intermediates contain a-methyl-platinum bonds. 

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