Hay oxidative coupling

In yet another approach towards the synthesis of cyclocarbons by cycloreversion, Adamson and Rees [71] prepared the 1,2,3-triazole-fused dehydroannulenes 42 - 44, as mixtures of regioisomers in ca. 30 % overall yield, by oxidative Hay coupling of the protected 4,5-diethynyl-l,2,3-triazole 41 (Scheme 7). No investigations have yet been reported on the thermal or mass spectrometric [3-1-2] cycloreversions of 42-44, with loss of the triazole moieties and ultimate formation of the cyclocarbons Cis, C24, and C30, respectively. 

Oxidative polymerization of trans-bis-deprotected 79 under Hay coupling conditions [54] yielded, after end-capping with phenylacetylene, the high-melting and readily soluble oligomers 80a-e with the poly (triacetylene) backbone [87,106] (Scheme 8). Poly(triacetylene)s [PTAs,-(C=C-CR=CR-C=C) -] are the third class of linearly conjugated polymers with a non-aromatic allcarbon backbone in the progression which starts with polyacetylene [PA,... 

Oxidative coupling of terminal acetylenes in the presence of copper(I) catalysts is the best method of preparing symmetrically substituted butadiyne derivatives,5 and has been applied to the coupling of trimethylsilyl-acetylene. Better yields are obtained using the Hay procedure in which the catalyst is the TMEDA complex of copper(I) chloride.7 The procedure submitted here is an improved version of Walton and Waugh s synthesis of BTMSBD by the Hay coupling of trimethylsilylacetylene.2 BTMSBD has also been prepared by... 

Metal coordination also enables organic ligands to be used as templates. Sanders and co-workers have synthesized cyclic porphyrin oligomers using Glaser-Hay coupling [16,40]. This reaction oxidatively combines two terminal acetylenes to give a 1,3-buta-diyne link. The syntheses of cyclic porphyrin dimer 38 and trimer 39 were effectively templated by 4,4 -bipyridine 37 and tripyridyltriazine 22, respectively (Scheme 1-10). 

The first method involves oxidative homo-coupling of bis (terminal alkynyl) complexes in the presence of a catalytic amount of a copper(I) halide and O2 as the oxidizing agent (Scheme 5.1, Eq. 5.1) [10]. The use of this catalyst system in organic synthesis is extensive and is better known as Hay s coupling reaction [11]. Extension of this methodology to organometallic synthesis was demonstrated by the conversion of trans-bis(acetylide) monomers into polymeric complexes. It is... 

Sometimes known as the Glaser-Hay coupling, it is the oxidative homo-coupling of terminal alkynes using copper catalyst in the presence of oxygen. 

Oxidative acetylenic coupling to produce 1,3-diynes is an important reaction with broad applications. Despite tremendous improvements in homocoupling processes, notably the Hay procedure, the construction of un-symmetrical conjugated diynes from two different terminal allqmes has only been recently reported. In 2009, Lei and co-workers described a copper/ nickel-co-catalyzed aerobic cross-coupling method that tolerated a variety of functional groups such as amides, halides and free propargylic alcohols (Scheme 9.24). ... 

The dione 174 only underwent oxidative coupling under Hay s conditions62 and afforded the cyclic dione 175. 

We were interested in the behaviour of polymeric catalysts in order to confirm that typical polymer effects may occur. Oxidative coupling of 2,6-disubstituted phenols, as developped by Hay (7), was chosen as a model reaction and the catalytic activities of coordination complexes of copper with several polymeric tertiary amines were compared with the activities of their low molecular weight analogs. The overall reaction scheme is presented in scheme 1. 

Poly(phenylene oxide) PPO, or poly(phenylene ether) PPE, is an engineering polymer developed by General Electric. It concerns the oxidative coupling of phenols discovered in 1956 by Allan S. Hay [21], Oxidative coupling leads to the formation of carbon-oxygen bonds between carbon atoms 2,4, and 6 and the phenolic oxygen atom. To avoid coupling with carbon atoms 2 and 6, alkyl substituents at these two positions were introduced. In addition to the polymer a 4,4 dimer is formed, named diphenoquinone (DPQ). The... 

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