Cadmium iodide, reaction

Titanium Dibromide. Titanium dibromide [13873-04-5] a black crystalline soHd, density 4310 kg/m, mp 1025°C, has a cadmium iodide-type stmcture and is readily oxidized to trivalent titanium by water. Spontaneously flammable in air (142), it can be prepared by direct synthesis from the elements, by reaction of the tetrabromide with titanium, or by thermal decomposition of titanium tribromide. This last reaction must be carried out either at or below 400°C, because at higher temperatures the dibromide itself disproportionates. 

The addition reaction requires the presence of 4 equivalents of HMPA, thus partial racemization of optically active aldehydes under these basic conditions is anticipated. Unfortunately, the addition of magnesium bromide, zinc chloride or cadmium iodide reverses the regioselectivity11 ... 

Diethylcadmium is prepared in turn by the reaction of cadmium iodide with triethylaluminum. 

In acid medium, cadmium iodide solution should exhibit the reduction reactions of I anion. Iodide anion is a fairly strong reducing agent which can reduce many metal ions in their higher oxidation states ... 

Acetylacetone la (10 mmol), metliyl vinyl ketone 2a (10 mmol) and bismuth trichloride (0.32 g, 10% mol) were mixed together without solvent in an Erlen-meyer flask and placed in a commercial microwave oven (operating at 2450 MHz frequency) and irradiated for 15 min. The reaction mixture was allowed to reach room temperature and extracted with chloroform. Removal of solvent and the residue on purification by passing through a short column of silica gel using chloroform as eluent, affords the Michael adduct 4a in 90% yield without tlie formation of any side products. Similarly cadmium iodide (10% mol) was used in place of bismuth trichloride and the corresponding Michael adduct was isolated in 85% yields. 

In a subsequent paper24, rate coefficients and activation parameters were given for reaction (10) in solvents methanol, ethanol, and dimethylformamide (DMF) details are also given in Table 3. The source of iodide ion was cadmium iodide, present in a ten-fold molar excess. 

The dependence of the value of k°2s, for reaction (10), on the iodide ion concentration has briefly been investigated. Using cadmium iodide as the source of iodide ion and methanol as the solvent, it was shown2 5 that kobs was independent of iodide ion concentration when the latter was present in two-fold excess or more. In addition, k°2s was also found to be independent of the source of iodide ion. A mechanism involving attack by I3- on the benzylmercuric halide was proposed, possibly through transition states (VI) or (VII)25. 

In the presence of AIH3 we have considered synthesis reaction of cadmium iodide at bombardment of mixture CdS + J [23] with hydrogen atoms. We have investigated catalytic properties of A1H3 at opening of different minerals [24]. 

The first example of utilizing a cadmium complex as a catalyst in enan-tioselective reaction was conjugate additions of thiols to cyclic enones and enals catalyzed by chiral iV -dioxide-cadmium iodide complex. The sulfides are generated in high yields and in good enantioselectivities up to 78% ee (323). 

After thorough desalination of the water phase of the wet oil samples by dialysis, the amide content was determined by reaction with bromine and, subsequently, cadmium iodide/starch reagent (6). For the calculation of the polymer concentration it must further be taken into account that the amide in the polymer gradually hydrolyzes in the course of the flood process, to form acrylate, a process affected by temperature and pH conditions. 

An alternative method, which avoids the prior preparation of the toxic di-alkylcadmiums, is direct reaction of the perfluoroalkyl iodide with cadmium metal [729] (equation 98)... 

Solvent plays a significant role in these reactions In contrast to the formation of organocadmium compounds in the duect reaction of perfluoroalkyl iodides and cadmium powder in DMF [729], dimerization of the perfluoroalkyl halide was observed in acetonitrile [777] (equation 100)... 

The perfluoroallylcadmium reagent can be prepared similarly by direct reaction of perfluoroallyl iodide with cadmium metal [146] (equation 113). Reaction of this cadmium reagent with ally bromide gives F2C=CFCp2CH2CH=CH2 in 78% yield [146]. 

The photochemical or thermal reaction between petfluoroalkyl iodides and mercury-cadmium amalgams has been used for the synthesis of perfluoro-alkylmercury compounds [150] Functionalized analogues have been prepared similarly via this route [151, 152] (equation 117), and the preparation of bis(tri-fluoromethyl)mercury has been described [153]... 

Codeposition of silver vapor with perfluoroalkyl iodides at -196 °C provides an alternative route to nonsolvated primary perfluoroalkylsilvers [272] Phosphine complexes of trifluaromethylsilver are formed from the reaction of trimethyl-phosphme, silver acetate, and bis(trifluoromethyl)cadmium glyme [755] The per-fluoroalkylsilver compounds react with halogens [270], carbon dioxide [274], allyl halides [270, 274], mineral acids and water [275], and nitrosyl chloride [276] to give the expected products Oxidation with dioxygen gives ketones [270] or acyl halides [270] Sulfur reacts via insertion of sulfur into the carbon-silver bond [270] (equation 188)... 

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