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Phenylacetylene is a prototypical terminal acetylene, undergoing many reactions expected of that functional group. It undergoes semi hydrogenation over Lindlar catalyst to give styrene . In the presence of base and copper(II) salts, it undergoes oxidative coupling to give diphenylbutadiyne . [ 6 ]
Yet another method involves the coupling of iodobenzene and the copper salt of phenylacetylene in the Castro-Stephens coupling. The related Sonogashira coupling involves the coupling of iodobenzene and phenylacetylene. Diphenylacetylene is a planar molecule. The central C≡C distance is 119.8 picometers. [1]
The Hay coupling is variant of the Glaser coupling. It relies on the TMEDA complex of copper(I) chloride to activate the terminal alkyne. Oxygen (air) is used in the Hay variant to oxidize catalytic amounts of Cu(I) to Cu(II) throughout the reaction, as opposed to a stoichiometric amount of Cu(II) used in the Eglington variant. [7]
It is a member of the diyne chemical class and can be made via the Glaser coupling of phenylacetylene [2] However, a variety of other synthesis methods have been developed. [3] [4] Diphenylbutadiyne forms a variety of metal-alkyne complexes. One example is the organonickel complex (C 5 H 5 Ni) 4 C 4 (C 6 H 5) 2. [5]
These reactions invariably involve metal-acetylide intermediates. This reaction was discovered by chemist John Ulric Nef in 1899 while experimenting with reactions of elemental sodium, phenylacetylene, and acetophenone. [3] [4] For this reason, the reaction is sometimes referred to as Nef synthesis.
A notable example of pheromone usage to indicate sexual receptivity in insects can be seen in the female Dawson's burrowing bee, which uses a particular mixture of cuticular hydrocarbons to signal sexual receptivity to mating, and then another mixture to indicate sexual disinterest. These hydrocarbons, in association with other chemical signals ...
Alkali metal and alkaline earth metal acetylides of the general formula MC≡CM are salt-like Zintl phase compounds, containing C 2− 2 ions. Evidence for this ionic character can be seen in the ready hydrolysis of these compounds to form acetylene and metal oxides, and by solubility in liquid ammonia with solvated C 2−
One example of the Strecker synthesis is a multikilogram scale synthesis of an L-valine derivative starting from Methyl isopropyl ketone: [5] (CH 3) 2 CHC(O)CH 3 + HCN + NH 3 → (CH 3) 2 CHC(CN)(NH 2)CH 3 + H 2 O. The initial reaction product of 3-methyl-2butanone with sodium cyanide and ammonia is resolved by application of L-tartaric acid ...