Subject from alkene hydrogenation

Metal-catalyzed oxidation of alcohols to aldehydes and ketones is a subject that has received significant recent attention [21,56,57]. One such method that utilizes NHC ligands is an Oppenauer-type oxidation with an Ir or Ru catalyst [58-62]. These alcohol oxidation reactions consist of an equilibrium process involving hydrogen transfer from the alcohol substrate to a ketone, such as acetone (Eq. 5), or an alkene. Because these reactions avoid the use of a strong oxidant, the potential oxidative instability of NHC ligands is less problematic. Consequently, these reactions represent an important target for future research into the utility of NHCs. 

Alkylrhodiums form from the reaction of Rh hydrides and alkenes. This reaction is important in hydrogenation, asymmetric hydrogenation, alkene isomerization and hydroformylation and other catalytic processes. The regiochemistry seen in this reaction is the subject of theoretical study that rationalizes the formation of the less substituted (T-alkyrhodium intermediate on electronic grounds Several Rh complexes form stable ff-alkylrhodiums on reaction of Rh hydrides with fluorinated alkenes (see Table 8) . 

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