Final answer:
H₂ addition with Pd/C catalyst is a syn addition, where hydrogen atoms are added to the same side of a double bond. The Pd/C catalyzed reactions are conducted under mild conditions and can be quite selective. Additives like AcOH may be used to enhance the reaction's efficiency and prevent catalyst poisoning.
Step-by-step explanation:
H₂ addition with Pd/C catalyst is a syn addition. This type of reaction involves the addition of hydrogen across a multiple bond, like an alkene, to produce an alkane. The Pd/C catalyst facilitates the hydrogenation process, adding hydrogen atoms to the same side of the carbon-carbon double bond, which is characteristic of a syn addition mechanism.
Such reactions are crucial in organic synthesis, particularly in the pharmaceutical industry, as they can be used to selectively reduce certain functional groups while leaving others intact. Hydrogenation reactions using a Pd/C catalyst are typically carried out under mild conditions compared to other types of catalytic reductions. The efficiency and selectivity of the reaction depend highly on the reaction conditions, including temperature, solvent, and the presence of other functional groups that could potentially interact with the catalyst.
In more complex organic molecules or in the presence of multiple functional groups, additives like AcOH may be required to facilitate the reaction by preventing catalyst poisoning and assisting in the reductive elimination step, as seen in the work on the phenylation of 6-arylpurine nucleosides.