Reaction of Benzene with Cyclohexene in the Presence of HF at 0°C

The reaction of benzene with cyclohexene in the presence of hydrofluoric acid (HF) at 0°C is a classic example of an electrophilic aromatic substitution reaction. In this reaction, the benzene ring undergoes substitution with the cyclohexene molecule in the presence of HF, forming a new substituted product.

Mechanism of the Reaction

The reaction mechanism can be divided into three stages, namely:

1. Formation of the electrophile: In the first stage, HF acts as a catalyst, and cyclohexene reacts with HF to form a carbocation. This carbocation acts as an electrophile in the subsequent reaction.

2. Attack of the electrophile: In the second stage, the carbocation formed in the first stage attacks the pi-electrons of the benzene ring. This results in the formation of a new intermediate species, which is positively charged.

3. Removal of the proton: In the final stage, the positively charged intermediate species loses a proton to form the final substituted product.

The overall reaction can be represented as follows:

Benzene + Cyclohexene + HF → Substituted product

Benefits of the Reaction

The reaction of benzene with cyclohexene in the presence of HF at 0°C is a very useful reaction as it allows the synthesis of a wide range of substituted products. The reaction is also highly selective, and the substituted product can be easily isolated and purified.

Conclusion

The reaction of benzene with cyclohexene in the presence of HF at 0°C is a classic example of an electrophilic aromatic substitution reaction. The reaction mechanism involves the formation of an electrophile, attack of the electrophile, and removal of the proton. The reaction is highly selective and allows the synthesis of a wide range of substituted products.