Addition Reaction

What is an Addition Reaction?

In the simplest of terms of organic chemistry, we can say that an addition reaction is a chemical reaction wherein two or more reactants come together to form a larger single product. But only chemical compounds containing multiple bond character can undergo an addition reaction as a double or triple bond is usually broken to form the required single bonds. An addition reaction is essentially a reverse decomposition reaction wherein a decomposition reaction is a reaction where one compounds one or more elements or compounds. Looking at an example of an addition reaction, hydrochlorination of propane (an alkene), for which the equation is

CH₃CH = CH₂ + HCl → CH₃C⁺HCH₃ + Cl⁻ → CH₃CHClCH₃

Types of Addition Reactions

For polar addition reactions there are two classifications, namely:

1. Electrophilic Addition reactions
2. Nucleophilic Addition reactions 

For non-polar addition reactions, we have two classifications, namely:

1. Free radical addition reactions
2. Cycloadditions reactions

Electrophilic addition: 

An electrophilic addition reaction can be described as an addition reaction in which a reactant with multiple bonds as in a double or triple bond undergoes has its π bond broken and two new σ bonds are formed.

Nucleophilic addition:

A nucleophilic addition reaction is an addition reaction where a chemical compound with an electron-deficient or electrophilic double or triple bond, a π bond, reacts with a nucleophile which is an electron-rich reactant with the disappearance of the double bond and creation of two new single, or σ, bonds.