Organic Reactions: Condensation, Hydrolysis, and Substitution

1. Organic Reactions: Condensation, Hydrolysis, and Substitution SCH4U0

2. Condensation • Condensation reactions are used to create esters, ethers, and amides • In each reaction, water is also a product • Acid is often used as a catalyst • In the example above; • The alcohol O attaches to the carbonyl carbon • The red atoms are removed as water

3. Mechanism - Condensation • For all condensation reactions, a nucleophilic atom reacts with an electrophilic atom • The nucleophile is usually the O in an alcohol or the N in an amine • The electrophile is typically a carbonyl carbon or the C in an alcohol • The nucleophilic atom forms a bond with the electrophilic carbon • At the same time, the electronegative group (red) accepts the electrons from the single bond and breaks off • Later, a base (likely water) removes the acidic proton

4. Condensation • We have seen how to use condensation to form esters, lets also create; Ethers Amides

5. Condensation Practice • Predict the products of the following condensation reactions

6. Hydrolysis • Hydrolysis reactions are the opposite of condensation • Water is used to break apart an ester, ether, or amide • Acids, and sometimes bases, can be used as catalysts • The oxygen in water attaches to the electrophilic carbon atom • This results in the electronegative group leaving

7. Mechanism - Hydrolysis • This mechanism is almost identical to the mechanism for condensation, a nucleophilic atom reacts with an electrophilic atom • The nucleophile is usually the O in water • The electrophile is typically a carbonyl carbon or the C in an ether • The nucleophilic atom forms a bond with the electrophilic carbon • At the same time, the electronegative group (red) accepts the electrons from the single bond and breaks off • Later, a base (likely water) removes the acidic proton

8. Hydrolysis Practice • Predict the products of the following hydrolysis reactions

9. Substitution • Substitution reactions are mechanistically very similar to condensation and hydrolysis reactions, but have different outcomes • Involves a nucleophile displacing an electronegative group • Results in the creation of amines, alcohols, ethers, and alkyl halides • The nucleophilic nitrogen reacts with the electrophilic carbon • The electronegative chlorine atom is displaced

10. Mechanism - Substitution • This mechanism is almost identical to the mechanism for condensation, a nucleophilic atom reacts with an electrophilic atom • The nucleophile is usually an O or N • The electrophile is typically a carbon attached to a halogen • The nucleophilic atom forms a bond with the electrophilic carbon • At the same time, the electronegative group (red) accepts the electrons from the single bond and breaks off • Later, a base (likely water) removes the acidic proton

11. Substitution • Alkyl halides can be formed using substitution as well. • These reactions require UV light as a catalyst • The halogen can substitute for any hydrogen • Multiple substitutions can occur (the main products are determined by stoichiometry and probability)

12. Substitution Practice • Predict the products of the following hydrolysis reactions