2018年12月3日 · One way to transform diazonium salts is by treating them with various compounds of copper. These are known as Sandmeyer reactions, after Traugott Sandmeyer who first discovered the reaction in 1884 (with copper acetylide!). Three key examples are: CuCN transforms aryl diazonium salts into aryl cyanides (nitriles).

Mechanism of the Rosenmund-von Braun Reaction. The mechanism probably involves the formation of a Cu(III) species through oxidative addition of the aryl halide. Subsequent reductive elimination then leads to the product:

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 …

Copper (I) cyanide (cuprous cyanide) is an inorganic compound with the formula CuCN. This off-white solid occurs in two polymorphs; impure samples can be green due to the presence of Cu (II) impurities. The compound is useful as a catalyst, in electroplating copper, and as a reagent in the preparation of nitriles. [4]

2020年11月28日 · The proposed mechanism suggests that the ethylbenzene-derived radical reacts with Cu II in an (L)Cu II (CN) 2 species to afford the benzyl-Cu III species. Subsequent C(sp 3)–CN reductive elimination generates the benzylic nitrile product.

2014年2月12日 · Considering the high-efficiency of copper catalysts in the activation of C–X, C–H, and C–B bond as well as in the formation of C–CN bond, this Letter summarizes various copper-mediated cyanations based on the different kinds of cyanide reagents, such as metal cyanides, potassium hexacyanoferrate (II), acetone cyanohydrins, DDQ, AIBN, benzyl cyan...

The exchange of halogen for cyano group by copper(I) cyanide, the Rosenmund–von Braun reaction, is a classical method of organic synthesis. The reaction is performed by prolonged heating with a stoichiometric amount or excess of CuCN in polar solvents at high temperatures.

2023年12月28日 · Sandmeyer Reaction is a chemical process that creates aryl halides from aryl diazonium salts using copper salts as reagents or catalysts. It is an example of a radical-nucleophilic aromatic substitution and provides a method for performing unique transformations on benzene, such as halogenation, cyanation, trifluoromethylation, and hydroxylation.

2021年8月7日 · Sandmeyer反应，是指重氮盐在CuX的催化下与卤素盐类反应产生卤代烃的化学反应，其中X可以为溴、氯或氰基负离子。 苯环上的取代基（如羟基，烷氧基，酰基，羧基，硝基和卤素等），无论是吸电子基团还是供电子基团，对反应都没有特别的影响，氯代必须用 CuCl/HCl 体系，溴代则要用CuBr/HBr 体系，碘代则一般用盐酸做重氮盐，不用Cu盐催化，直接加KI或NaI 就能得到碘苯。 一百多年来，由于 芳香重氮化合物 活性高，容易制备，工艺成熟，使其在化 …

2014年3月24日 · 芳香重氮盐的一系列转化：在CuCN作用下、可得到相应的苯腈。 若用CuCl、CuBr处理，则能得到对应的卤代衍生物。 和碘化钠加热则得碘代衍生物、由四氟硼酸银处理得到氟硼酸重氮盐，加热后得到氟代衍生物(参见 Balz-Schiemann反应 )。