Electrophillic addition of HCl to 2-methyl-2-propene?
The electrophilic addition of HCl to 2-methyl-2-propene involves the addition of a hydrogen chloride (HCl) molecule to the carbon-carbon double bond of 2-methyl-2-propene. In this reaction, the pi bond of the alkene acts as the nucleophile, while the hydrogen chloride molecule acts as the electrophile.
To understand the reaction mechanism, we need to consider the electron distribution in both the reactant and the product. In 2-methyl-2-propene, the carbon-carbon double bond has a pi bond, which consists of a region of electron density above and below the plane of the molecule. Meanwhile, hydrogen chloride (HCl) is a polar molecule, meaning it has a partially positive hydrogen atom and a partially negative chlorine atom.
The reaction proceeds in the following steps:
1. The pi bond of the double bond in 2-methyl-2-propene acts as a nucleophile and attacks the partially positive hydrogen atom in HCl. This leads to the formation of a new bond between the carbon atom of 2-methyl-2-propene and the hydrogen atom of HCl.
2. As a result of this bond formation, the pi bond is broken, and electrons from the double bond are used to form a bond with the chlorine atom from HCl. The chlorine atom becomes negatively charged.
3. In the final step, a chloride ion (Cl-) acts as a base and removes the hydrogen atom from the positively charged carbon atom, resulting in the formation of a chloride ion and a carbocation intermediate.
4. The carbocation intermediate can then be attacked by another chloride ion, resulting in the formation of a chloroalkane product.
To summarize, the electrophilic addition of HCl to 2-methyl-2-propene involves the addition of HCl across the double bond, resulting in the formation of a chloroalkane product. It proceeds through a reaction mechanism involving the attack of the pi bond as a nucleophile, the formation of a carbocation intermediate, and the attack of a chloride ion as a base.