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.
Upon completing this LO students should be able to
- Describe what benzyne is and how it is formed
- Explain the coordination of benzyne (and therefore all alkynes) as L type donors to a metal center
- Use the CBC method to count electrons in all of the compounds and intermediates in this study
- Rationalize reaction pathways using electron counting techniques
- Explain 195Pt satellites
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.