Electrophilic Substitution: Mechanisms and Selectivity

This lecture delves into the concepts of electrophilic substitution reactions, focusing on mechanisms and selectivity. The instructor starts by questioning the students about the importance of the course and then proceeds to discuss various reactions such as nitration, sulfonation, and chloromethylation. The lecture covers the formation of sigma complexes, resonance structures, and the impact of electron-donating and electron-withdrawing groups on reaction selectivity. The instructor emphasizes the relationship between reactivity and selectivity, highlighting the role of reaction conditions, temperature, and solvents. The lecture concludes with a discussion on the factors influencing selectivity, including steric hindrance and the presence of multiple directing groups.