Eglinton coupling

Oxidative homo-coupling of terminal alkynes mediated by stoichiometric (or often excess) Cu(OAc)2. A variant of the Glaser coupling reaction. 

Shanmugam, P. Vaithiyananthan, V. Viswambharan, B. Madhavan, S. Tetrahedron Lett. 2007,48,9190-9194. 

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The dimerization of terminal alkynes, known as the Glaser coupling, the Eglinton coupling, and the Cadiot-Chodkiewicz coupling, is one... 

Four donor acceptor [2]catenanes possessing cyclobis(paraquat-p-phenylene), as the 7i-electron acceptor, and 1,5-dioxynaphthalene-containing macrocyclic polyethers, as the 7i-electron donor moieties, have been constructed employing Cu+-catalyzed Huisgen 1,3-dipolar cycloaddition and Cu+2-mediated Eglinton coupling condition in the final step <07JA8236>. Desymmetrized [2]catenanes were synthesized by means of a template synthesis of pseudorotaxanes between 7i-rich crown ethers and a 7i-deficient pyromellitic subunit,... 

Although copper acetylides seem to be able to perform a nucleophilic substitution reaction at the sp-carbon atom of a bromo- or iodoacetylene (Cadiot-Chodkievicz reaction), this reaction has only rarely been used for the preparation of cyclic 1,3-diacetylenes. Copper-mediated oxidative coupling reactions (Glaser, Hay and Eglinton coupling) are more popular in this area and have attracted much attention in the construction of carbon-rich cyclic and polycyclic systems (see Chapter 13). One of the earliest carbon-rich systems of this type was the CzoHg system 19 [11,16] [Eq. (5)]. 

Other references related to the Eglinton coupling are cited in the literature. 

Eglinton coupling by changing the reagent or solvent Following this strategy we have synthesized the macrobicyclic hosts 30a and 30b in a two step synthesis from the trisphenols 28a,b. 

The 1,3-butadiyne units in 29 and 33-35 act as rigid framework which spans a cavity for guests (see below). This function of a polyalkyne unit was also used to construct cavities with receptor properties. Among monocydic receptors were 36 and 37 with two and three n units and two and three butadiyne spacers [41, 42]. Both were constructed by Eglinton coupling. Other cyclic systems which form intracavity complexes are the cyclophanes 38 and 39 [43, 44] (Chart 7.1). 

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