Freshman Organic Chemistry II with Michael McBride - 10. Cation Intermediates. Alkenes: Formation, Addition, and Stability

Freshman Organic Chemistry II (CHEM 125B) Bridged pentavalent carbon structures can be intermediates or transition states of cation rearrangement during SN1 reactions, and short-lived ion pairs explain net stereochemical inversion. The different perspectives of preparative organic chemists and mechanistic organic chemists on reaction yields are illustrated by a study designed to demonstrate that molecular rotation can be rate-limiting in viscous solvents. "Electrophilic" addition to alkenes is the reverse of E2 or E1 reaction, and its mechanisms can be studied by analogous techniques. The NIST Webbook provides thermochemical data to help understand the relative stability of isomeric alkenes. 00:00 - Chapter 1. Rearrangement of Cation Intermediates 10:20 - Chapter 2. Studying SN1 and E1 Mechanisms: Stereochemistry and Rate 17:13 - Chapter 3. Preparative and Mechanistic Perspectives on Competing Reactions 20:51 - Chapter 4. Preparing t-Butylhydrazine to Study Rate-Limiting Motion 36:46 - Chapter 5. "Electrophilic" Addition to Alkenes 41:41 - Chapter 6. NIST Webbook and the Stability of Isomeric Alkenes Complete course materials are available at the Open Yale Courses website: http://oyc.yale.edu This course was recorded in Spring 2011.