Submitted by Chip Nataro / Lafayette College on Mon, 01/23/2017 - 14:02
My Notes
Categories
Prerequisites
Organic Chemistry
Corequisites
No Corequisites
Course Level
Upper Division/Graduate
Topics Covered
Bonding models: Discrete molecules
Chemical literature
Molecular structure
Physical methods / analytical techniques
Reaction mechanisms
Synthesis and reactivity
Subdiscipline
Organometallic Chemistry
Description

The literature discussion is based on a paper by Gagné (Organometallics 2015, 34, 2707).  In this work, the in situ generation of benzyne is examined. The benzyne coordinates to a platinum center with a tridentate (pincer) phosphine ligand and a methyl group. This provides an opportunity to discuss the characterization of compounds that have NMR active nuclei that are not 100% naturally abundant. Protonation of the benzyne compound results in the formation of toluene. Different mechanisms are considered.

Attachment Size
Questions for students 19.83 KB
Learning Goals

Upon completing this LO students should be able to 

  1. Describe what benzyne is and how it is formed
  2. Explain the coordination of benzyne (and therefore all alkynes) as L type donors to a metal center
  3. Use the CBC method to count electrons in all of the compounds and intermediates in this study
  4. Rationalize reaction pathways using electron counting techniques
  5. Explain 195Pt satellites
Related activities
CBC (Covalent Bond Classification) Method of Electron Counting
Electron Counting and CBC Assignments for Organometallic Complexes
Kecking over Electron Counting Formalisms? An In-Class Exercise in Counting Electrons for Ru Complexes with Proton-Responsive Ligands in the CBC and Ionic Methods
Synthesis and Migratory-Insertion Reactivity of CpMo(CO)<sub>3</sub>(CH<sub>3</sub>): Small-Scale Organometallic Preparations Utilizing Modern Glove-Box Techniques
Energetics and mechanisms of reductive elimination from Pt(IV)
Time Required
50 minutes or so
Web Resources
The paper
Benzyne formation
Evaluation
Evaluation Methods

This was developed after the semester in which I teach this material. I look forward to using it next fall and I hope to post some evaluation data at that point.

Creative Commons License
Attribution, Non-Commercial, Share Alike CC BY-NC-SA