Markovnikov and anti-Markovnikov addition are two important addition reactions in organic chemistry that involve the migration of a hydrogen atom from a carbon...
Markovnikov and anti-Markovnikov addition are two important addition reactions in organic chemistry that involve the migration of a hydrogen atom from a carbon atom to another, resulting in the formation of a more substituted alkene or alkane.
The Markovnikov addition occurs when a hydrogen atom migrates from the more substituted carbon atom to the less substituted one. The more substituted carbon atom is more electron-rich and, thus, more nucleophilic. This allows the hydrogen atom to migrate to the less substituted carbon atom more readily.
The anti-Markovnikov addition occurs when a hydrogen atom migrates from the less substituted carbon atom to the more substituted one. The more substituted carbon atom is less electron-rich and, thus, less nucleophilic. This allows the hydrogen atom to migrate to the more substituted carbon atom more readily.
Both Markovnikov and anti-Markovnikov additions involve the formation of a carbocation intermediate, which is a species with a carbon atom with a positive charge. The carbocation intermediate can then rearrange itself to form a more stable alkene or alkane product.
Here are some examples of Markovnikov addition:
When an alkene is exposed to hydrogen and platinum, the hydrogen atom migrates to the carbon atom with the most hydrogen atoms.
When an alkene is treated with bromine in water, the bromine atom migrates to the carbon atom with the more hydrogen atoms.
Here are some examples of anti-Markovnikov addition:
When an alkane is exposed to hydrogen and palladium, the hydrogen atom migrates to the carbon atom with the more hydrogen atoms.
When an alkane is treated with bromine in water, the bromine atom migrates to the carbon atom with the less hydrogen atoms