Early Examples of Hydrocarbon Activation

Prior to 1982, Crabtree s report of the reaction of cyclopentane with a solvated IrH2(PPh3)2+ species to give a cyclopentadienyl-iridium product stood as the only well characterized example of a reaction of an alkane with a homogeneous transition metal, in contrast to the widespread reactivity of arenes [2]. Based upon the instability of the platinum methyl hydride complex Pt(PPh3)2(CH3)H, it was believed that alkane oxidative addition might not be a thermodynamically feasible process, and consequently few attempts were made to attempt such a reaction [3]. It was not until the discovery of the formation of stable alkane oxidative addition products in 1982 that it was realized that reactions of hydrocarbons were in fact feasible. 

The first reports were based upon reactions of the [Cp IrL] fragment where L=PMe3 or CO and Cp =r 5-C5Me5 by Bergman and Graham, respectively [4,5]. A less stable alkane oxidative addition product to the fragment [Cp Rh(PMe3)] was also reported by Jones [6]. In all of these cases, irradiation was used to either 

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