Organic Chemistry Reactions: What Is It and the Different Types of It

Eager to learn more about organic chemistry reactions? Then you are on the right page. In this complete guide, learn what organic reactions are and their mechanisms and types.

What Are Organic Chemistry Reactions

Organic chemistry reactions are reactions involving organic compounds. The basic organic reactions in chemistry can be classified as addition reactions, elimination reactions, rearrangement reactions, substitution reactions, etc. Organic synthesis uses organic reactions to build new organic molecules. The production of many man-made chemicals such as pharmaceuticals, plastics, food additives, and textiles relies on organic reactions.

The Organic Chemistry Reactions Mechanism

The mechanism of organic chemistry reactions usually involves several fundamental steps involving the breaking or forming of chemical bonds. These procedures can be categorized into three general types:

1. Nucleophilic substitution (SN1 and SN2)

Nucleophilic substitution reactions involve the substitution of nucleophiles (electron-rich species) of atoms or groups. The SN1 mechanism proceeds through a two-step process. The first step is the formation of a carbocation intermediate, followed by a nucleophilic attack. The SN2 mechanism, on the other hand, involves a coordinated one-step process in which a nucleophile directly displaces a leaving group.

2. Electrophilic additions

Electrophilic addition reactions occur when electrophiles (electron-deficient species) react with nucleophiles. These reactions typically involve the addition of electrophiles across carbon-carbon double or triple bonds, resulting in the formation of new bonds at each carbon.

3.Elimination (E1 and E2):

In an elimination reaction, two adjacent atoms or groups are removed to form a double or triple bond. The E1 reaction begins with the formation of a carbocation intermediate and proceeds through its two-step process of leaving group loss and proton abstraction. In contrast, the E2 reaction proceeds in a coordinated, one-step process in which a strong base abstract a proton and simultaneously removes a leaving group. 

Types of Organic Chemistry Reactions

As mentioned before, organic chemistry reactions have a variety of types. In the following, figure out the common types of organic reactions and learn them separately.

l Addition reaction

Addition reactions occur when two or more reactants combine to form a product without losing any atoms present in the reactants. Addition reactions are common in compounds containing unsaturated C-C bonds. B. Double bonds (alkenes) and triple bonds (alkynes). The weaker π bond is transformed into two new stronger σ bonds.

l Elimination reaction

There are several reactions in which adjacent atoms or groups are removed or eliminated. Multiple bonds are then formed and small molecules are released as products. An example of an elimination reaction is the conversion of ethyl chloride to ethylene. CH₃CH₂Cl → CH₂=CH₂ + HCl

In the above reaction, the molecule removed is HCl, formed by combining H+ on the left carbon atom with Cl- on the right carbon atom.

l Rearrangement reaction

Rearrangement reactions can accompany many of the previously discussed reactions, including substitution, addition, and elimination reactions. Such reactions are relatively rare. In fact, if you are not careful, you may miss the fact that a rearrangement reaction is taking place. This reaction can also be called an oxidation reaction. 

l Substitution reaction

Substitution reactions replace one atom or group with another, forming a new substance. For example, the conversion of methane to chloromethane is a substitution reaction in which hydrogen atoms are replaced by chlorine atoms.

l Acid/base reaction

Another important category of organic reactions is the simple Bronsted-Lowry acid-base reaction. Like any acid-base reaction, it has four "players" in this reaction, all of whom have names.

The reactant that breaks the bond with H is an acid.

The reactant in which the H bond is formed is a base.

The product formed when the bond with H is broken is called the conjugate base.

Products resulting from bond formation with H are called conjugate acids. 

l Radical reaction

Radicals are involved in many organic reactions. Halogen addition to saturated hydrocarbons occurs via a free radical mechanism. Free radical reactions involve three stages: initiation, propagation, and termination. When weak bonds are broken, the reaction first begins with the formation of free radicals. When a halogen is then added to a hydrocarbon, a radical is formed and eventually, an alkyl halide is formed. 

Conclusion

Organic chemistry reactions play an important role in understanding the synthesis and transformation of organic compounds. These reactions are based on fundamental principles and concepts that enable chemists to develop innovative strategies in drug development, materials science, and environmental sustainability. By learning more about those reactions, you can better understand and apply them.