Carbocations and the Mechanism of Electrophilic Addition to Alkenes and Alkynes - Lecture 11

Explore the mechanisms of electrophilic addition to alkenes and alkynes in this 52-minute lecture from Yale University's Freshman Organic Chemistry II course. Delve into alkene thermochemistry and various addition mechanisms, including free-radical, metal-catalyzed, and stepwise electrophilic processes. Examine carbocation stability through concepts like hyperconjugation, hybridization, and solvation. Investigate the Markovnikov addition, methide shift in carbocations, and the intriguing rates of stepwise addition of HCl or HBr to alkynes. Gain insights into how halogen substituents can act as both electron-withdrawing and electron-donating groups. The lecture covers five main chapters: Alkene Thermochemistry, Alkene Addition Mechanisms, Understanding Carbocation Stabilities, Skeletal Rearrangement of Carbocations, and Stepwise Addition to Alkynes.