Search results
Results from the WOW.Com Content Network
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 ]
Cyanobacteria such as these carry out photosynthesis.Their emergence foreshadowed the evolution of many photosynthetic plants and oxygenated Earth's atmosphere.. Biological carbon fixation, or сarbon assimilation, is the process by which living organisms convert inorganic carbon (particularly carbon dioxide, CO 2) to organic compounds.
In addition the molecule is naturally produced by the metapleural gland of most ant species and used as an antimicrobial. It is also the oxidation product of phenethylamine in humans following metabolism by monoamine oxidase and subsequent metabolism of the intermediate product, phenylacetaldehyde , by the aldehyde dehydrogenase enzyme; these ...
The reaction provides a means to generate alkynes from alkenes, which are first halogenated and then dehydrohalogenated. For example, phenylacetylene can be generated from styrene by bromination followed by treatment of the resulting of 1,2-dibromo-1-phenylethane with sodium amide in ammonia: [9] [10]
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]
Palladium precatalyst species are activated under reaction conditions to form a reactive Pd 0 compound, A. The exact identity of the catalytic species depends strongly upon reaction conditions. With simple phosphines, such as PPh 3 (n=2), and in case of bulky phosphines (i.e., P(o-Tol) 3) it was demonstrated that monoligated species (n=1) are ...
In animals and in prokaryotes, beta-ketoacyl-ACP synthase is a domain on type I FAS, which is a large enzyme complex that has multiple domains to catalyze multiple different reactions. Analogously, beta-ketoacyl-ACP synthase in plants is found in type II FAS; note that synthases in plants have been documented to have a range of substrate ...
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.