Contact Information

Author
  • James E. Hutchison
  • Professor
  • Chemistry
  • Univ. of Oregon
  • Eugene, OR 97403
Email
Phone
(541) 346 - 4228
Website

Oxidative Coupling of Alkynes: The Glaser-Eglinton-Hay Coupling

Laboratory Procedures (PDF)

Author Contact: hutch@uoregon.edu

Summary

The Glaser-Eglinton-Hay reaction has been used to synthesize a number of fungal antibiotics and is important for carbon-carbon bond formation via the oxidative coupling of alkynes. This laboratory exercise illustrates the oxidative coupling of 1-ethynylcyclohexanol in the presence of cuprous chloride, tetramethylethylenediamine and air. Typically, pyridine has been used as a solvent in this type of reaction, but a greener solvent, 2-propanol, is used in this procedure.

A complex mechanism has been proposed for this copper catalyzed coupling reaction. The acetylide, formed by deprotonation of the terminal alkyne, reacts with the cuprous chloride to produce a copper (Cu+1) acetylide complex. Air is bubbled through the reaction solution to oxidize Cu+1 to Cu+2. The Cu+2 is then reduced to Cu+1, resulting in the formation of the alkyne coupling product. The link to the laboratory procedure includes post-lab questions.

Summary prepared July 2005 by Christine K. F. Hermann, Department of Chemistry and Physics at Radford University.

Source

Doxsee, K. M.; Hutchison, J. E. Green Organic Chemistry - Strategies, Tools, and Laboratory Experiments, Print 2004; pp 142-151.

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Category Descriptors

Chemistry Concepts
  • Alkynes
  • Catalysis
  • Oxidation/Reduction Chemistry
Laboratory Techniques
  • Assembly of Reaction Apparatus
  • Decolorization
  • IR Spectroscopy
  • Measuring Mass and Volume
  • Melting Points and Melting Ranges
  • Recrystallization
  • Rotary Evaporation
  • Thin-layer Chromatography
  • Vacuum Filtration
Green Chemistry Principles
  • Design Less Hazardous Chemical Syntheses
  • Increase Energy Efficiency
  • Maximize Atom Economy
  • Prevent Waste
  • Use Catalysts
  • Use Safer Solvents/Reaction Conditions
Chemistry Subdiscipline
  • Organic Chemistry
Target Audience
  • Colleges/Universities
Source
  • Books