Mechanisms: electrophilic addition Flashcards
What group forms what group in this reaction?
Alkenes form alkanes
What is the general equation?
Alkene + reagent —> 1 product
What happens to the double bond in the alkene?
It becomes a single bond. An electrophile is often needed to break the double C bond
What are carbocations?
A positive charge on carbon atom
What is a primary carbocation?
Where there is 1 other carbon atom attached to carbocation
What is a secondary carbocation?
Where there is 2 other carbon atoms attached to carbocation
What is a tertiary carbocation?
Where there is 3 other carbon atoms attached to carbocation
What do R1, R2 and R3 stand for on the structure of carbocations?
Alkyl groups such as methyl and ethyl. They can all be the same or different
What is Markownikoff’s rule?
- Methyl and ethyl groups have an electron releasing effect relative to H atom
- The more stable the carbocation, the longer the time is remains in the reaction mixture
- Which means it has a greater chance of reacting with an anion to form a product
What do more stable carbocations form?
Major products
What do less stable carbocations form?
Minor products
What do electrophilic addition reactions go via?
An intermediate carbocation
Which type of carbocation is most stable and which is least stable?
A tertiary carbocation is most stable so it becomes major product relative to others
A primary carbocation is least stable so becomes minor product
