Copper compounds, synthesis

Stibonium Ylids and Related Compounds. In contrast to phosphoms and arsenic, only a few antimony yhds have been prepared. Until quite recendy triphenyl stibonium tetraphenylcyclopentadienyUde [15081 -36-4] C H Sb, was the only antimony yUd that had been isolated and adequately characteri2ed (192). A new method, uti1i2ing an organic copper compound as a catalyst, has resulted ia the synthesis of a number of new antimony yhds (193) ... 

The Ullman reaction has long been known as a method for the synthesis of aromatic ethers by the reaction of a phenol with an aromatic halide in the presence of a copper compound as a catalyst. It is a variation on the nucleophilic substitution reaction since a phenolic salt reacts with the halide. Nonactivated aromatic halides can be used in the synthesis of poly(arylene edier)s, dius providing a way of obtaining structures not available by the conventional nucleophilic route. The ease of halogen displacement was found to be the reverse of that observed for activated nucleophilic substitution reaction, that is, I > Br > Cl F. The polymerizations are conducted in benzophenone with a cuprous chloride-pyridine complex as a catalyst. Bromine compounds are the favored reactants.53,124 127 Poly(arylene ether)s have been prepared by Ullman coupling of bisphenols and... 

On the basis of this information, techniques for the synthesis of pure copper compounds were developed. The following parameters played an important role ... 

Fluoroalkyl copper compounds, 17 143, 144 a-Fluoroalkylidinehydrazines, 33 167 2-Fluoroalky 1 -2 phospha-1,3-dialky 1 -1,3-diaze-tidinones, synthesis of, 14 87 Fluoroanions, trivalent, uranium, 34 94—95 Fluoroantimony compounds, 7 17 Huoroaryl copper compounds, 17 143, 144 Fluoroberyllates anhydrous, 14 267-276 aqueous chemistry of, 14 274-278 glasses, 14 265-267 preparation and properties of, 14 265-267... 

Boron-sulfur bonds, addition, to alkynes, 10, 778 Boron trihalides, in boron compound synthesis, 9, 146 Boron-zinc exchange and copper-catalyzed substitutions, 9, 518 for organozinc halide preparation, 9, 89 Borostannylation, enynes, 10, 334... 

The Ullmann reaction (Figure 13.4) represents another synthesis of substituted biphenyls. In this process an aryl iodide or—as in the present case—an aryl iodide/aryl chloride mixture is heated with Cu powder. It is presumed that under standard conditions the aryl iodide reacts in situ with Cu to form the aryl copper compound. Usually, the latter couples with the remaining aryl iodide and a symmetric biphenyl is formed. In a few instances it is also possible to generate asymmetric biaryls via a crossed Ullmann reaction. In these cases one employs a mixture of an aryl iodide and another aryl halide (not an iodide ) the other aryl halide must exhibit a higher propensity than the aryl iodide to couple to the arylcopper intermediate. It is presumed that the mechanism of the Ullmann reaction parallels the mechanism of the Cadiot-Chodkiewicz coupling, which we will discuss in Section 13.4. 

The reaction of Gilman reagents with ,)8 -epoxy-oximes yields -hydroxy-ketones [e.g. (17 X=OH)].56 Vinyl copper compounds are converted stereo-specifically into /3,/3-disubstituted a-ethylenic acids by carbonation nerol (18) was synthesized (Scheme 3).57 Further papers on /3-ketosulphoxide synthesis [e.g. of... 

Two reviews have detailed the reactions of aryl halides with copper and copper compounds these are (1) the Ullmann biaryl synthesis, by Fanta 113) and (2) copper-promoted reactions, by Bacon and Hill (9). The mechanism of the Ullmann biaryl synthesis was discussed the possible routes are shown in Eq. (110). No evidence had been obtained... 

Fluorocarbon organometallic compounds [198, 199] are discussed more generally in Chapter 10, but polyfluoroaryl-lithium, -magnesium and -copper compounds are particularly important in organic synthesis, as outlined below. 

Copper compounds [215] An interesting contrast occurs between phenyl- and penta-fluorophenyl-copper compounds, in that the fluorinated derivatives are considerably more stable [216-220] and are useful reagents in organic synthesis (Figure 9.86). 

Alkynylation of zinc-copper compounds has been used for the synthesis of polyfunctional acetylenic ethers [84] and for the preparation of building blocks for pharmaceutically active compounds [85]. Whereas cross-coupling between non-activated iodoalkenes and zinc-copper reagents only proceeds at elevated temperatures and in polar solvents such as NMP or DMPU (60 12 h) [86], alkenyl... 

The Industrial synthesis of methylchlorosilanes is a heterogeneous gas-solid-synthesis, in which silicon powder is reacted with an excess of chloromethane in the presence of finely divided copper or copper compounds in fluidized bed reactors at temperatures of ca. 350°C. 

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