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Halogenation of benzene where X is the halogen, catalyst represents the catalyst (if needed) and HX represents the protonated base. A few types of aromatic compounds, such as phenol, will react without a catalyst, but for typical benzene derivatives with less reactive substrates, a Lewis acid is required as a catalyst.
A tetrachlorophenol is any organochloride of phenol that contains four covalently bonded chlorine atoms. Tetrachlorophenols are produced by electrophilic halogenation of phenol with chlorine. [1] Different isomers of tetrachlorophenol exist according to which ring positions on the phenol contain chlorine atoms. There are three different isomers:
In chemistry, halogenation is a chemical reaction which introduces one or more halogens into a chemical compound. Halide-containing compounds are pervasive, making this type of transformation important, e.g. in the production of polymers, drugs. [1] This kind of conversion is in fact so common that a comprehensive overview is challenging.
An early example concerns the addition of chloral to phenols catalyzed by aluminium chloride modified with (–)-menthol. [6] A glyoxylate compound has been added to N,N-dimethylaniline with a chiral bisoxazoline ligand–copper(II) triflate catalyst system also in a Friedel–Crafts hydroxyalkylation: [7] Asymmetric Friedel–Crafts ...
The chemical complexity of coffee is emerging, especially due to observed physiological effects which cannot be related only to the presence of caffeine. Moreover, coffee contains an exceptionally substantial amount of antioxidants such as chlorogenic acids, hydroxycinnamic acids, caffeine and Maillard reaction products, such as melanoidins. [3]
They may be viewed as hydroxyl derivatives of bromobenzene, or as brominated derivatives of phenol. There are five basic types of bromophenols (mono- to pentabromophenol) and 19 different bromophenols in total when positional isomerism is taken into account. Bromophenols are produced by electrophilic halogenation of phenol with bromine.
The most commonly employed Sandmeyer reactions are the chlorination, bromination, cyanation, and hydroxylation reactions using CuCl, CuBr, CuCN, and Cu 2 O, respectively. More recently, trifluoromethylation of diazonium salts has been developed and is referred to as a 'Sandmeyer-type' reaction.
A chlorophenol is any organochloride of phenol that contains one or more covalently bonded chlorine atoms. There are five basic types of chlorophenols (mono- to pentachlorophenol) and 19 different chlorophenols in total when positional isomerism is taken into account. Chlorophenols are produced by electrophilic halogenation of phenol with ...