Sabatier-Senderens Reduction (From Unsaturated Hydrocarbons)

$$\text{R--CH=CH}_2 + \text{H}_2 \xrightarrow{\text{Ni / Pt / Pd}, \, \Delta} \text{R--CH}_2\text{--CH}_3$$

Concept: Alkene or alkyne double/triple bonds undergo addition of hydrogen gas ($$H_2$$) in the presence of a finely divided metal catalyst ($$\text{Ni}$$, $$\text{Pt}$$, or $$\text{Pd}$$) to yield saturated hydrocarbons (alkanes).

Reagents & Conditions:

Finely divided Nickel ($$\text{Ni}$$) at $$250\text{--}300^\circ\text{C}$$, or Platinum ($$\text{Pt}$$) / Palladium ($$\text{Pd}$$) at room temperature.

Key Notes:

• This process is an addition reaction (heterogeneous catalysis).
• Used industrially for hydrogenation of vegetable oils to form solid fats (vanaspati ghee).