Question

Write an equation for a coupling reaction.

Answer 1

Coupling reaction refers to the class of organic reactions that involve the joining of two chemical species usually with the help of a metal catalyst i.e. it is a reaction in which two fragments are joined together with the aid of a metal catalyst.

Complete step by step answer:
Coupling reaction is a class of organic reaction in which two chemical species are joined together with the help of a metal catalyst.
When benzene diazonium chloride reacts with phenol in which the phenol molecule at its para position coupled with the diazonium salt to form p- hydroxyazobenzene. This is known as the coupling reaction.
The reaction is as shown:

We have two types of coupling reactions:
Homo-coupling reaction: In this type of reaction, two chemical species are combined to yield a single product. E.g. Wurtz coupling, pinacol coupling, Glaser coupling.
Hetero-coupling (also known as cross coupling) - In these type of reactions, two dissimilar chemical species are joined together to afford a single product.e.g. Grignard reaction, Suzuki coupling.

Note:
Coupling reactions are employed in the synthesis of several pharmaceutical products. Many conjugated polymers are prepared via these reactions that involve the use of a metal catalyst. Moreover, the Suzuki coupling reaction is also used in the synthetic production of complex compounds.