Hydrogenation and Other Reduction Reactions

Asymmetric Catalytic Hydrogenation and Other Reduction Reactions... 

ASYMMETRIC CATALYTIC HYDROGENATION AND OTHER REDUCTION REACTIONS... 

Lin G-Q, Li Y-M, Chan ASC. Asymmetric catalytic hydrogenation and other reduction reactions. In Principles and applications of asymmetric synthesis. New York Wiley 2001. p 331-389. 

For oxidation by atmospheric oxygen a sample in an EPR tube may simply be opened to air and stirred. However, reaction with any other gas than air requires special handling of the sample on the manifold of a Schlenk line. Examples are oxidation by pure oxygen, reduction by hydrogen, and also the reaction by any gaseous substrate or inhibitor such as CO, C02, NO, N20, etc. Basically, there are two different experimental approaches mixing with a solution in which the gas is dissolved or mixing with a pressurized atmosphere of the gas. 

Fig. 3. Schematic illustration of the synthesis of metal nanoparticles within dendrimer templates. The composites are prepared by mixing of the dendrimer and metal ion, and subsequent chemical reduction. These materials can be immobilized on electrode surfaces where they serve as electrocatalysts or dissolved in essentially any solvent (after appropriate end-group functionalization) as homogeneous catalysts for hydrogenation and other reactions...

Only modest differences in activity were observed when the decomposition (56) or synthesis (21) of ammonia over Ti02-supported catalysts were compared after LTR and HTR. Similarly, small effects of reduction temperature were observed for the self-hydrogenation of C2H4 (100). On the other hand, the decomposition of formic acid appears to be favored over Rh/Ti02 reduced at high temperature (101). This reaction, like CO hydrogenation and NO reduction, takes place under partially oxidizing conditions that can, at least partially, reverse the SMSI state. 

---