Material Detail

Lecture 8 - Solvent, Leaving Group, Bridgehead Substitution, and Pentavalent Carbon

Lecture 8 - Solvent, Leaving Group, Bridgehead Substitution, and Pentavalent Carbon

This video was recorded at CHEM 125b: Freshman Organic Chemistry II. The nature of nucleophiles and leaving groups has strong influence on the rate of SN2 reactions. Generally a good nucleophile or strong base is a poor leaving group, but hydrogen-bonding solvents can alter nucleophile reactivity. Although amino and hydroxyl groups are poor leaving groups, they may be converted to groups that leave easily, even from bridgehead positions. Designing the preparation of a sugar analogue containing radioactive fluorine shows how understanding the SN2 mechanism enables PET scanning for medical imaging. Quantum mechanics suggests that the pentavalent carbon species on the SN2 reaction pathway is a transition state, not a stable structure.
Rate

Quality

  • Editor Reviews
  • User Rating
  • Comments
  • Learning Exercises
  • Bookmark Collections
  • Course ePortfolios
  • Accessibility Info

More about this material

Comments

Log in to participate in the discussions or sign up if you are not already a MERLOT member.