2100-42-7Relevant articles and documents
Homogeneous catalysis and selectivity in electrochemistry
Michman, Michael,Appelbaum, Lina,Gun, Jenny,Modestov, Alexander D.,Lev, Ovadia
, p. 4729 - 4737 (2014)
The relationship between homogeneous catalysis and electrochemistry is examined in light of two examples based on our work concerning (a) catalyst activation, regarding selective electrochemical C-H oxidation with RuIII/RuIV mediation, and (b) catalyst suppression, regarding controlling selectivity in electrochemical aromatic chlorination. The first example (a) deals with the role of catalysis at the working electrode. The electrochemical (EC) oxidation of specific hydrocarbons such as tetralin and indane is performed using tris(acetonitrile)ruthenium trichloride (Ru(CH3CN)3Cl3) as a mediator. The role of this mediator in the oxidation of tetralin has been reported. This homogeneous C-H activation by electron transfer (ET) is accompanied by the redox transitions of the mediator in the course of the catalytic oxidation, and these are the main points of interest here. Additional studies with a rotating ring disk electrode (RRDE) provided a follow-up of creation and recovery of RuIII/RuII and RuIII/RuIV species in the process. Using electrochemistry linked with electrospray ionization mass spectrometry (EC/ESI-MS) gave additional information on the structure of the reduced and oxidized forms of Ru(CH3CN)3Cl3 and the effect of water in the solvent on their lifetimes. The second example (b) of electrochlorination has been reported elsewhere and is brought up as complementary remarks. Aromatic electrophilic chlorination of 1,4-dimethoxy-2-tertbutylbenzene is autocatalyzed and unselective. The EC procedure provides a simple means to inhibit the catalytic runaway reaction. This example shows how the counter electrode affects catalysis and selectivity. (Figure Presented)
Efficient halogenation synthesis method of aryl halide
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Paragraph 0184-0186, (2021/03/31)
The invention discloses an efficient halogenation synthesis method of aryl halide. The method comprises the following step: in the presence of a catalyst (sulfoxide or oxynitride), a halogenation reagent and a solvent, carrying out a halogenation reaction on an aromatic ring compound to obtain the aryl halide. According to the present invention, in the presence of a catalyst (sulfoxide or nitrogenoxide), a halogenation reagent and a solvent, the aromatic ring is subjected to an efficient halogenation reaction, such that the very useful aryl halide can be obtained with high activity and high selectivity; and by adopting the method disclosed by the invention, aryl halides can be efficiently synthesized, and the method has a wide application prospect in actual production.
Preparation method of 2,5-dimethoxychlorobenzene
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Paragraph 0029; 0032-0033; 0038-0042, (2020/12/15)
The invention relates to a preparation method of 2,5-dimethoxychlorobenzene, which comprises the following steps: 1) one-pot oxidatiion and chlorination: dissolving phenol in a solvent, putting a formed solution into a high-pressure reaction kettle, adding a copper salt catalyst, conducting stirring to conduct reaction at a temperature range of room temperature to 50 DEG C under the oxygen pressure of 0.5-3 MPa, introducing 0.1-2 MPa dry HCl gas into the solution after the reaction is completed, and conducting stirring to conduct reaction at room temperature, and after the reaction is completed, conducting decompressing and rectifying to obtain a 2-chlorohydroquinone intermediate; and 2) methylation: adding 2-chlorohydroquinone into a high-pressure reaction kettle, conducting dissolving, introducing 0.1-2MPa of chloromethane gas under an alkaline condition, maintaining the pressure, conducting reacting at 50-120 DEG C until the raw materials are completely consumed, conducting filtering and desolventizing, and carrying out reduced pressure distillation to obtain the product 2,5-dimethoxychlorobenzene. Compared with a traditional preparation method, the method has the advantages ofless emission of three wastes, low cost, environmental friendliness and the like.
Preparation, structure, and oxidative reactivity of (dichloroiodo)pyridines: Recyclable hypervalent iodine reagents
Yoshimura, Akira,Nguyen, Khiem C.,Nemykin, Victor N.,Zhdankin, Viktor V.
, p. 40 - 49 (2018/02/07)
New pyridine-based hypervalent iodine reagents, (dichloroiodo)pyridines, were prepared by chlorination of 2-, 3-, or 4-iodopyridines with NaOCl-HCl at room temperature. Structures of 2-(dichloroiodo)pyridine and 2-(dichloroiodo)-3-propoxypyridine were established by X-ray crystallography. The new (dichloroiodo)pyridines can be used as efficient reagents for oxidation of alcohols to carbonyl compounds and also as chlorinating reagents. The reduced form of the reagents such as 2-iodo-3-propoxypyridine, can be recovered from the reaction mixture in good yields by an acid-base liquid-liquid biphasic protocol.