Nickel diiodo

Displacement of aromatic halogen in 2,4-diiodo-estradiol with tritiated Raney nickel yields 2,4-ditritiated estradiol. Aromatic halogen can also be replaced by heating the substrate with zinc in acetic acid-OD or by deuteration with palladium-on-charcoal in a mixture of dioxane-deuterium oxide-triethylamine, but examples are lacking for the application of these reactions in the steroid field. Deuteration of the bridge-head position in norbornane is readily accomplished in high isotopic purity by treatment of the... 

TURMIC1 Diiodo-bis(l,3-diisopropylimidazolidine-2,4,5-trithionato)-nickel(II) bis(l,3-diisopropylimidazolidine-2,4,5-trithionato)-nickel(II) diiodine 2.849 2.790 178.78 BA... 

Mellor, 1947, Vol. 8, 1061 1971, Vol. 8, Suppl. 3, 348, 335, 373 Tetraphosphorus tetraoxide trisulfide or neodymium phosphide are violently oxidised, nickel tetraphosphide ignites with the finning acid, and tetraphosphorus diiodo triselenide reacts explosively with nitric acid. 

The electrochemistry of cobalt-salen complexes in the presence of alkyl halides has been studied thoroughly.252,263-266 The reaction mechanism is similar to that for the nickel complexes, with the intermediate formation of an alkylcobalt(III) complex. Co -salen reacts with 1,8-diiodo-octane to afford an alkyl-bridged bis[Co" (salen)] complex.267 Electrosynthetic applications of the cobalt-salen catalyst are homo- and heterocoupling reactions with mixtures of alkylchlorides and bromides,268 conversion of benzal chloride to stilbene with the intermediate formation of l,2-dichloro-l,2-diphenylethane,269 reductive coupling of bromoalkanes with an activated alkenes,270 or carboxylation of benzylic and allylic chlorides by C02.271,272 Efficient electroreduc-tive dimerization of benzyl bromide to bibenzyl is catalyzed by the dicobalt complex (15).273 The proposed mechanism involves an intermediate bis[alkylcobalt(III)] complex. 

A 50-ml Schlenck tube equipped with a stirring bar containing bis(l,5-cyclooc-tadiene)-nickel(O) (4.48 mmol), 2,2 -bipyridyl (4.48 mmol), and 1,5-cycloocta-diene (4.48 mmol) was treated with 5 ml of DMF and the ensuing deep blue/ purple solution stirred at 60°C for 30 minutes. The mixture was then treated with 2,7-diiodo-9,9-bis(2-ethylhexyl)fluorene (1.68 mmol) and 2,5-bis(p-bromo-phenyl)-A-(p-hexylphenyl)pyrrole (0.56 mmol) in 20 ml of toluene by syringe and then stirred for 5 days at 75°C. The solution was cooled to ambient temperature and precipitated into a mixture of 100 ml apiece of methanol and acetone and 5 ml concentrated hydrochloric acid. After of the mixture was stirred for 2 hours, it was filtered the solid residue was dissolved in chloroform and re-precipitated in methanol and acetone solution, and re-filtered. The residue was successively washed with methanol, water and methanol, and dried the product was isolated having a Mj, of 47,200 daltons. 

Several tricyclic monomers required for oxidative (electrochemical or chemical) polymerization have been prepared by coupling reactions. Thus, l,4-diiodo-2,5-dimethylbenzene was coupled with 2-thienylmagnesium bromide in the presence of nickel(II) bis(diphenylphosphino)propane dibromide (NidpppBr2). However when methoxy groups were present in the benzene ring ortho to the site of coupling, the decreased electrophilicity necessitated the use of a more nucleophilic thiophene derivative, 2-thienylcopper (Equation (60)). 

Cyclohexene-l-one, methyl vinyl ketone, phenylacetylene, diphenylacety-lene, benzaldehyde, perfluoro-l-heptene, and cyclohexene were found to not be effective dienophiles for the reaction. Only polymeric o-xylylene products were seen in the reaction mixture. In addition, no cycloadduct was produced by using / -benzoquinone as the dienophile. Only hydroquinone and a,a -diiodo-o-xylene were recovered. The hydroquinone presumably results from the reduction of benzoquinone by nickel. Since sodium iodide is known to react with dibromo-o-xylene to give diiodo-o-xylene [112], the diiodo-o-xylene could result from the reaction of unconsumed dibromo-o-xylene with lithium iodide which is present in the reaction flask. These results are analogous to those reported in a similar reaction by Scheffer [113], where the use of zinc metal and ultrasound gave only hydroquinone and a quantitative yield of the unreacted dibromo-o-xylene. 

C26H20I2N2Ni, (2,9-Dimethy1-4,7-diphenyl-1,10-phenanthroline)diiodo-nickel(II), 43B, 1334... 

C31H3 5AS212NNiO, Diiodo-(N,N-bis(2-diphenylarsinoethyl)-2-methoxy-ethylamino)nickel(II), 39B, 859... 

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