Which of the following catalyst is/are used for partial reduction of alkyne ?

Options

A. `Na//NH_(3)(l)`
B. `Ni_(2)B` or P-2 catalyst
C. Lindlar catalyst
D. Rossenmud catalyst

Answer

To determine which catalysts are used for the partial reduction of alkynes, we need to analyze the options provided and understand the role of each catalyst in the reduction process.

### Step-by-Step Solution:

1. **Understanding Partial Reduction of Alkynes**:
- Partial reduction of alkynes involves the addition of hydrogen (hydrogenation) to convert alkynes (R-C≡C-R) into alkenes (R-C=C-R) without fully reducing them to alkanes (R-CH2-CH2-R).

2. **Analyzing the Catalysts**:
- **Option A: Sodium in Liquid Ammonia**:
- Sodium in liquid ammonia is known to facilitate the conversion of alkynes to trans alkenes. This process involves partial reduction and is indeed a valid catalyst for this reaction.

- **Option B: Na2B10H12 (Borane)**:
- Na2B10H12 (often referred to as sodium borohydride) is also used for the partial reduction of alkynes, leading to the formation of cis alkenes. This catalyst is effective in hydrogenation reactions.

- **Option C: Lindlar Catalyst**:
- The Lindlar catalyst, which consists of palladium on calcium carbonate (or barium carbonate), is specifically designed for the partial hydrogenation of alkynes to cis alkenes. It is poisoned to prevent complete reduction to alkanes, making it suitable for this purpose.

- **Option D: Rosin's Catalyst**:
- Rosin's catalyst (palladium on barium sulfate) is primarily used for the reduction of acyl chlorides to aldehydes and is not used for the partial reduction of alkynes.

3. **Conclusion**:
- The catalysts that can be used for the partial reduction of alkynes are:
- **A: Sodium in Liquid Ammonia**
- **B: Na2B10H12 (Borane)**
- **C: Lindlar Catalyst**
- Therefore, the correct options are A, B, and C.

### Final Answer:
The catalysts used for the partial reduction of alkynes are:
- A: Sodium in Liquid Ammonia
- B: Na2B10H12 (Borane)
- C: Lindlar Catalyst