Copper compounds iodide

The oxidation reaction between butadiene and oxygen and water in the presence of CO2 or SO2 produces 1,4-butenediol. The catalysts consist of iron acetylacetonate and LiOH (99). The same reaction was also observed at 90°C with Group (VIII) transition metals such as Pd in the presence of I2 or iodides (100). The butenediol can then be hydrogenated to butanediol [110-63-4]. In the presence of copper compounds and at pH 2, hydrogenation leads to furan (101). 

Determination. The most accurate (68) method for the deterrnination of copper in its compounds is by electrogravimetry from a sulfuric and nitric acid solution (45). Pure copper compounds can be readily titrated using ethylene diamine tetracetic acid (EDTA) to a SNAZOXS or Murexide endpoint. lodometric titration using sodium thiosulfate to a starch—iodide endpoint is one of the most common methods used industrially. This latter titration is quicker than electrolysis, almost as accurate, and much more tolerant of impurities than is the titration with EDTA. Gravimetry as the thiocyanate has also been used (68). 

The formation of g-alkyl-a,g-unsaturated esters by reaction of lithium dialkylcuprates or Grignard reagents in the presence of copper(I) iodide, with g-phenylthio-, > g-acetoxy-g-chloro-, and g-phosphoryloxy-a,g-unsaturated esters has been reported. The principal advantage of the enol phosphate method is the ease and efficiency with which these compounds may be prepared from g-keto esters. A wide variety of cyclic and acyclic g-alkyl-a,g-unsaturated esters has been synthesized from the corresponding g-keto esters. However, the method is limited to primary dialkylcuprates. Acyclic g-keto esters afford (Zl-enol phosphates which undergo stereoselective substitution with lithium dialkylcuprates with predominant retention of stereochemistry (usually > 85-98i )). It is essential that the cuprate coupling reaction of the acyclic enol phosphates be carried out at lower temperatures (-47 to -9a°C) to achieve high stereoselectivity. When combined with they-... 

The perfluoroacetylenic copper compounds undergo coupling reactions with aryl iodides and provide a useful synthetic route to the perfluoroalkyl aryl alkynes [147, 255] (equation 170) Coupling of these copper reagents with the 1-iodo-perfluoroalkynes gives the perfluorodiynes [747 255] (equation 171)... 

The reaction of these acetylenic copper compounds with perfluorovinyl iodides stereospecifically gives the perfluoroeneynes [147, 755] (equations 172 and 173). 

The analogous trifluoromethylseleno and pentafluorophenylseleno copper compounds are prepared via reaction of the corresponding diselenide with copper metal [265, 269] Coupling with aryl iodides gives the arylselenium denvative [265] (equation 185)... 

Iodide ions reduce Cu to Cu , and attempts to prepare copper(ll) iodide therefore result in the formation of Cul. (In a quite analogous way attempts to prepare copper(ll) cyanide yield CuCN instead.) In fact it is the electronegative fluorine which fails to form a salt with copper(l), the other 3 halides being white insoluble compounds precipitated from aqueous solutions by the reduction of the Cu halide. By contrast, silver(l) provides (for the only time in this triad) 4 well-characterized halides. All except Agl have the rock-salt structure (p. 242). Increasing covalency from chloride to iodide is reflected in the deepening colour white yellow, as the... 

Cupro-. cuprous, copper(I), cupro-. -chlorid, n. cuprous chloride, copper(I) chloride, -cy-aniir, n. cuprous cyanide, copper(I) cyanide cuprocyanide, cyanocuprate(I). -jodid, n. cuprous iodide, copper(I) iodide, -mangan, n. cupromanganese. -oxyd, n. cuprous oxide, copper(I) oxide, -salz, n. cuprous salt, cop-per(I) salt, -suifocyantir, n. cuprous thiocyanate, copper (I) thiocyanate, -verbin-dUDg, /. cuprous compound, copper(I) compound. 

One particularly valuable reaction of alkyllithiums is in making lithium diorganocop>per compounds, UR2CU, by reaction with copper(l) iodide in... 

Many reactions have been shown to benefit from irradiation with ultrasound (ref. 19). We therefore decided to investigate the effect of ultrasound, different catalysts and the presence of solids on Ullmann diaryl ether synthesis. Indeed, sonication of mixtures of a phenol and a bromoaromatic compound, in the absence of solvent and presence of copper (I) iodide as catalyst and potassium carbonate as base, produces good yields of diaryl ethers at relatively low temperatures (Fig. 10) (ref 20). 

CHROMIUM TRIOXIDE-PYRIDINE COMPLEX, preparation in situ, 55, 84 Chrysene, 58,15, 16 fzans-Cinnamaldehyde, 57, 85 Cinnamaldehyde dimethylacetal, 57, 84 Cinnamyl alcohol, 56,105 58, 9 2-Cinnamylthio-2-thiazoline, 56, 82 Citric acid, 58,43 Citronellal, 58, 107, 112 Cleavage of methyl ethers with iodotri-methylsilane, 59, 35 Cobalt(II) acetylacetonate, 57, 13 Conjugate addition of aryl aldehydes, 59, 53 Copper (I) bromide, 58, 52, 54, 56 59,123 COPPER CATALYZED ARYLATION OF /3-DlCARBONYL COMPOUNDS, 58, 52 Copper (I) chloride, 57, 34 Copper (II) chloride, 56, 10 Copper(I) iodide, 55, 105, 123, 124 Copper(I) oxide, 59, 206 Copper(ll) oxide, 56, 10 Copper salts of carboxylic acids, 59, 127 Copper(l) thiophenoxide, 55, 123 59, 210 Copper(l) trifluoromethanesulfonate, 59, 202... 

As to catalytic reactions in homogeneous media, Moritz Traube found in his studies of the oxidation of hydrogen iodide by hydrogen peroxide in aqueous solution, that the catalyst ferrous sulfate is activated by copper sulfate (5). As to the magnitude of such effects, Price stated in 1898 (6) that the simultaneous action of iron and of copper compounds on the reaction between persulfate and hydrogen iodide causes an unexpected acceleration of the reaction, which is more than twice as great as the acceleration calculated as an additive effect of the two single catalysts. However, effects were also observed of the opposite kind,... 

Elemental composition Cu 33.36%, I 66.64%. Either compound or mineral copper(I) iodide is identified by x-ray diffraction or fluorescence method. Copper may be analyzed in nitric acid extract of copper(I) iodide by various instrumental techniques (see Copper). 

Due to the cost of trifluoromethyl iodide, other cheaper sources have been investigated for trifluoromethylation. Sodium trifluoroacetate reacted with aryl iodide in the presence of copper (I) iodide in NMP at 140 -160 °C to afford the corresponding coupling product [87]. No trifluoromethylation was observed without Cul. Under similar reaction conditions, sodium pentafluoropro-pionate worked well to give the pentafluoroethylated compounds [88, 89] (Scheme 28). 

Thallation also provides a route to 4-iodoindoles from the related 3-acyl compounds. Here the intermediate thallium compound can be treated with iodine and copper(I) iodide in DMF to effect the transformation (84H(22)797,93JCS(Pl)256l). 

Bicyclobutanes are also obtained from the catalytic decomposition of diazo compound 17492 (equation 51). Copper(I) iodide was the catalyst of choice, whereas rhodium(II) acetate did not show any activity in this case. When the related diazo compound 175 was decomposed, the product pattern depended in an unusually selective manner on the catalyst92. Intramolecular cyclopropanation leading to 176 is obviously less favorable than for carbene 172 and must yield to the 1,2-hydride shift not observed with the former carbene. The configuration of the resulting butadiene 177 can be completely reversed by the choice of the catalyst. 

The coupling of terminal acetylenic compounds with the reactive allylic bromides in the presence of l,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and copper(i) iodide appears to be a useful route to the non-conjugated enyne system, e.g. the formation of hex-5-en-2-yn-l-ol.46... 

Because of the toxicity of cadmium compounds two alternative methods for the preparation of ketones from carboxylic acid derivatives are worthy of attention. The first involves the reaction of organocopper reagents [formed from copper(i) iodide and an alkyllithium] with a carboxylic acid chloride.12 7a,b... 

All of the neutral (organo-)copper compounds just listed can be arylated by aryl iodides and/or -bromides Ar-Cu and R-C=C-Cu can also be alkynylated by alkynyl iodides and/or -bromides. Table 16.2 summarizes the whole spectrum of corresponding products. After having grasped the mechanism of these reactions by way of Figure 16.3, we will discuss their synthetic potential by means of the examples given in Figures 16.4-16.9. 

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