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Halonium ylides can be prepared from allyl halides and metal carbenoids. After a [2,3]-rearrangement, a homoallylhalide is obtained. After a [2,3]-rearrangement, a homoallylhalide is obtained. The active form of Tebbe's reagent is often considered a titanium ylide.
Pyridinium refers to the cation [C 5 H 5 NH] +. It is the conjugate acid of pyridine. Many related cations are known involving substituted pyridines, e.g. picolines ...
Ylides are regarded as positively charged heteroatoms connected to negatively charged carbon atoms, which include ylides of sulfonium, thiocarbonyl, oxonium, nitrogen, and carbonyl. [36] Several methods exist for generating carbonyl ylides, which are necessary intermediates for generating oxygen-containing five-membered ring structures, for [3 ...
Pyrylium salts are easily produced from simple starting materials through a condensation reaction. [2]Pyrylium salts with aromatic substituents, such 2,4,6-triphenylpyrylium tetrafluoroborate, can be obtained from two moles of acetophenone, one mole of benzaldehyde, and excess tetrafluoroboric acid. [3]
Pyridinium compounds (37 P) T. Thienopyridines (10 P) Pages in category "Pyridines" The following 200 pages are in this category, out of approximately 253 total.
Radical dimerization of pyridine with elemental sodium or Raney nickel selectively yields 4,4'-bipyridine, [91] or 2,2'-bipyridine, [92] which are important precursor reagents in the chemical industry. One of the name reactions involving free radicals is the Minisci reaction.
Chain propagation: A radical reacts with a non-radical to produce a new radical species; Chain termination: Two radicals react with each other to create a non-radical species; In a free-radical addition, there are two chain propagation steps. In one, the adding radical attaches to a multiply-bonded precursor to give a radical with lesser bond ...
Zincke aldehydes, or 5-aminopenta-2,4-dienals, are the product of the reaction of a pyridinium salt with two equivalents of any secondary amine, followed by basic hydrolysis. Using secondary amines (as opposed to primary amines) the Zincke reaction takes on a different shape forming Zincke aldehydes in which the pyridine ring is ring-opened ...