Sodium cuprate

EPOXIDES Alumina. Bisfbenzonltrile)-dichloropalladium(H). Copper(II) sulfate-Pyridine. Diborane. Diphenyl d isu Ifide-Tri-n-bu t y Iphosphine. Organo-cuprates. Sodium cyanoborohydride. Sodium phenyl selenide. Trimethyl-sllyl phenyl sclcnidc. Trimethylsilyl trifluoromethanesulfonate. Triphenyl-phospliine-Thiocyanogen. 

The superconducting oxides include both perovskites and Ruddlesden-Popper compounds which have an orthorhombic arrangement of cubic cells, alternatively of the perovskite and sodium chloride structures. The common feature of all of these is the presence of copper as a major component. The first ceramic superconductor was a lanthanum-strontium substituted cuprate (Lai Sr Cu04 z), which is a perovskite, but subsequently the inter-oxide compound Y203 2BaO 3CuO, commonly referred to as a 123 compound, was shown to have superior performance. The speculation concerning the conduction mechanism is that this involves either Cu3+-Cu2+ positive hole... 

The reaction of aminoguanidine with sodium nitrite under neutral conditions yields tetra-zolylguanyltetrazene hydrate (85), a primary explosive commonly known as tetrazene. Tetrazene (85) is only formed in the absence of free mineral acid and so a common method for its preparation treats the bicarbonate salt of aminoguanidine (84) with one equivalent of acetic acid followed by addition of aqueous sodium nitrite. " Tetrazene (85) is decomposed by aqueous alkali to form triazonitrosoaminoguanidine (86) which is isolated as the cuprate salt (87) on addition of copper acetate to the reaction mixture. Acidification of the copper salt (87) with mineral acid leads to the formation of 5-azidotetrazole (88) (CHN7 = 88 % N).55 56... 

By dissolving Cu(N3)2 in aq or ale solns of NaN, Straumanis Cirulis (Ref 98) obtd sodium triazido-cuprate Na [Cu(Nj)3]( anhyd after heating above 120°. This compd exploded at 216-23° and under impact of drop hammer. Explosion also took place when Hg (N03)2 was added to Na[Cu(N3)3l (Ref 98). The addn of NaN3 to an amine soln of Cu++ salts pptd complex non-electrolytes (Ref 97).Wiberg ... 

Allylic phosphorus compounds Tris(tetrabutylammonium) pyrophosphate, 338 Allylsilanes t-Butyllithium, 58 Chlorotrimethylsilane-Lithium, 81 Lithium bis(dimethylphenylsilyl)-cuprate, 161 Methyllithium, 188 Trichlorosilane-t-Amines, 322 Allylic sulfur compounds (Phenylsulfonyl)allene, 247 Sodium benzenesulfinate, 289... 

As stated above, intermolecular coupling reactions between carbon atoms are of limited use. In the classical Wurtz reaction two identical primary alkyl iodide molecules are reduced by sodium. n-Hectane (C100H202), for example, has been made by this method in 60% yield (G. Stallberg, 1956). The unsymmetrical coupling of two alkyl halides can be achieved via dialkylcuprates. The first halide, which may have a branched carbon chain, is lithiated and allowed to react with copper(I) salts. The resulting dialkylcuprate can then be coupled with alkyl or aryl iodides or bromides. Although the reaction probably involves radicals it is quite stereoselective and leads to inversion of chiral halides. For example, lithium diphenyl-cuprate reacts with (R)-2-bromobutane with 90% stereoselectivity to form (S)-2-phenylbutane (G.M. Whitesides, 1969). 

Sodium cuprate yielded less reduction product and less thiophilic addition product than lithium cuprate at both —50 and 0 °C. In the case of silyl thiones chiral at silicon, the reactions with organolithium derivatives and Grignard reagents produce a-silylsulfides with medium to good levels of asymmetric induction and, interestingly, the asymmetry induced at the a-carbon is retained in the subsequent desilylation431 (equation 118), the process being stereoselective. 

SYNS COPPER SODIUM CYANIDE CUPRATE(2-), TRIS(CYANO-C)-, DISODIUM SODIUM CUPROCYANIDE, solid (UN 2316) (DOT) SODIUM CUPROCYANIDE, solution (UN 2317) (DOT)... 

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