Copper with dihalides

With dihalides of cobalt(II) and nickel(II), such as the chlorides, bromides and iodides, as well as with the thiocyanates, tetrahedral complexes with general formula MeXa (HMPA>2 are formedAs may be expected these compounds are non-conductors in a solvent of very low donor number, such as nitromethane. Likewise the disolvates of certain metal nitrates, such as cobalt(II), nickel(II) or copper(II) appear to have the nitrate groups located within the coordination spheres. The compound Co(N03)2 (HMPA)2 contains Co(II) in pseudotetra-hedral C2V environment. Cu(N03)2(HMPA)2 is thought to be a planar complex, while in Ni(N03)2(HMPA)2 a distorted tetrahedral structure appears to be present... 

Primary, secondary, and tertiary aliphatic amines have been cleaved to give aldehydes, ketones, or carboxylic acids with aqueous bromine and with neutral permanganate. The other product of this reaction is the amine with one less alkyl group. In a different type of procedure, primary alkyl primary amines can be converted to ge/n-dihalides, RCH2NH2 —> RCHX2 (X =Br or Cl), by treatment with an alkyl nitrite and the anhydrous copper(I) halide. 

Synthesis. These macrocycles are prepared from seven-membered ring dinitrile complexes, 84a-84c (Scheme 17), which contain either methylene, sulfur or oxygen in the five position (129). These cyclic dinitriles are synthesized by alkylating maleonitrile dithiolate or derivatives thereof with the corresponding dihalide. The dinitriles 84a-84c can be cyclized in magnesium propoxide to form porphyrazines 85a (33%), 85b (19%), and 85c (27%) (Scheme 17), which can be demetalated with trifluoroacetic to form 86a-86c. Additionally, 86a has been remetalated with nickel (87a, 92%), copper (88a, 95%), and zinc (89a, 94%). The sulfur and oxygen derivatives 85b, 85c, 86b, and 86c are of low solubility and are not suitable for further manipulation. 

Diaryl tellurium compounds are converted to diaryl tellurium dihalides through reactions with sulfur tetrafluoride1, triaryl bismuth difluorides2-3, copper(II) halides4,5, iron(III) chloride, and mercury(II) chloride4. 

CUCI2 has been studied spectroscopically at 1000 °C in the presence of CI2 (to prevent decomposition to CuCl and Cb). Binary copper compounds with very soft iodide ligands are not known by simply adding 1 to a solution of Cu +, Cul and I2 are quickly formed. This reaction can be used for the volumetric analysis of Cu + in solution by titrating the I2 produced with sodium thiosulfate (equation 8). Hydrates of the dihalides (F, Cl, Br) are common, easily prepared from aqueous haloacids, and contain coordinated water molecules. 

For work-up of the reaction mixtures, reagents which destroy the nitrile-copper cyanide complexes, for instance Fe /HCl (oxidation of Cu to Cu , followed by extraction of the nitrile), ethylenediamine (complexation of Cu ions) or an excess of aqueous NaCN (formation of the soluble NaCu(CN)2), proved to be particularly useful. With appropriate ortho substituents, such as carboxy groups, cyclization reactions may be observed under the reaction conditions. If treated at higher temperatures with CuCN, o-dihalides often provide phthalocyanines. 

Reactivity follows the sequence RI > RBr > RC1, and SnL > SnBr2 > SnCl2. The uncatalysed reaction of methyl iodide with stannous iodide at 160 °C has been reported,72 but usually a catalyst is necessary. These catalysts are similar to those which are used for the direct reactions, and include dialkyl sulphides, amines, ammonium and phosphonium salts, and copper(II). The trialkylstibines appear to be particularly effective and the compounds RSnX3, R = Ci to Cis, have been prepared by this method. A similar reaction with the a,co-dihalides, X(CH2) X, n = 4-5, provides access to functionally substituted tetraorganotin compounds, but the aryl halides are unreactive. 

It was shown by us that the reaction of P with CF3I is not limited to the condensed or liquid phase. Red phosphorus is also alkylated by trifluoro-iodomethane vapor over a copper catalyst The products are the same as in the liquid reaction but in reduced yield and different composition. The mono-and dialkylated compounds are the major products wliich is the reverse of the liquid system where the tris (trifluoromethyl)phosphine is usually the dominant product. This indicates that the phosphorus dihalide is a primary product of the reaction and not a decomposition or disproportionation product. 

Furtliermore, we could show that the reaction is not limited to perfluoroalkyl iodides. When methyl or ethyl halides were passed through a mixture of red phosphorus and copper at around 350 °C mainly phosphorus dihalides were produced. The phosphinous halide is formed in small amount along with some phosphines. With methyl bromide, e.g., the reaction product is composed of 80-90% CH3PBr2, 2-3% (Cf j-PBr and 7-14% (CH3)2PBr3. 

Similarly, alkenyldiiodonium salts (48) reacted with sodium halide and copper(I) halide salts to afford the vinyl dihalide derivatives (49) in modest to good yields. 6... 

The dihalides, RgShHaLg, may be obtained by heating mercury diphenyl with antimony trichloride at a high temperature in an autoclave, or as by-products in the preparation of triarylstibmes by the Fittig reaction. Halogens also add on directly to triarylstibines, gi nng the dihalides, and in the case of chlorine, the following chlorides may replace the free element in the preparation copper, iron, thallium, phosphorus or arsenic chloride. 

C yclopropanes. The reaction of alkenes with em-dihalides and copper icsiills in cyclopropane derivatives, often in good yields. The reaction is carried tint in a lellnxing aromatic hydrocarbon benzene, toluene, ethylbenzene. 

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