In the experiment Thiamine Catalyzed Benzoin Condensation wh

Solution

The two types of catalysts typically used are:

1) Cyanide ion

2) Vitamin Thiamine

Advantages of Cyanide:

1) It is a strong Nucleophile

2) Intermediates are easily isolable

3) Facilitates proton transfer

4) Stabilizes negative charge on the adehyde intermediate (Cabanion).

5) It is a good leaving group

Disadvantages of Cyanide:

1) It is highly toxic

2) Not ideal for Electron withdrawing or electron donating groups

3) Has geometric restrictions.

Advantages of Thiamine:

1) It has the right balance of nucleophillicity

2) It is a universal coenzyme present in all living systems, hence it is a \"Green catalyst\" and is not toxic like CN^-

3) The reaction can be conducted at lower temperature, which can eliminate biproducts.

4) Stereoselective and Bioselective.

4) No geometric restrictions, hence wide appliacbility to aldehydes, unlike CN^-

Disadvantages of Thiamine:

1) Needs a coenzyme to be present