Eglinton coupling

What is Eglinton coupling?

In 1956, Eglinton first reported the Eglinton coupling reaction which involves the oxidative coupling of terminal alkynes using stoichiometric amounts of copper (II) acetate [Cu(OAc)2] in pyridine. This reaction is also known as the Eglinton method, Eglinton methodology, Eglinton coupling reaction, Eglinton oxidative coupling, Eglinton-Glaser reaction, Eglinton reaction, and Eglinton condition.

Eglinton coupling - general reaction scheme - Eglinton method - Eglinton methodology - Eglinton coupling reaction - Eglinton oxidative coupling - Eglinton-Glaser reaction - Eglinton reaction - Eglinton condition
Eglinton coupling

When carried out in methanolic pyridine, the reaction can be homogenous. The Eglinton coupling reaction is particularly useful for preparing linearly conjugated all-carbon chains (polyacetylenes) or cyclic dimers, trimers, tetramers, and even pentamers of compounds with two terminal alkynyl groups. Interestingly, the homocoupling of 3,6-di-(t-butyl)-3,6-dihydroxyl-1,4,7-octa-triynes with Cu(OAc)2 produces cyclic dimers in pyridine, whereas the solid-state reaction with Cu(OAc)2·2Py yields linear coupling products.

The coupling of terminal alkynes using this reaction has extensive applications, particularly in the creation of cyclic alkynes.

References

Eglinton, G. and Galbraith, A. R., “Cyclic dyinesChemistry & Industry, 1956, 28, 736-737

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