Arene-metal complexes Preparation

Arene-displacement reactions, characteristics, 1, 97 Arene-ene substrates, in C-H bond alkylation, 10, 218 Arene-ferracarboranes, characteristics, 3, 225-226 I // -Arene liruliiim complexes, preparation, 7, 388 (Arene)metal(diborolyl) sandwiches, synthesis, 3, 12... 

Other stable (arene)2Cr complexes prepared by the metal atom technique are listed in Table 2. 

The most reactive of the common arene-metal complexes has been the least developed with regard to nucleophilic substitution for halide. It is only an improved, gentler method of complexation that allowed isolation of the fluorobenzene complex with Mn(CO)3+. The chlorobenzene analog is easily prepared and undergoes substitution with alkoxy. 

The Friedel-Crafts method is the most versatile route available for preparing arene-metal complexes, having been applied successfully to nearly a dozen transition metals. The method has definite limitations, however, with regard to the type of arene unit used, and only alkyl- and aryl-substituted benzenes in general can be successfully employed. 

Exchange of one arene ligand for another is potentially a powerful method for preparing of arene-metal complexes. With bis(jj -arene)metal complexes, only a few examples are known with no systematic development. Equilibrium of bis(>/ -benzene)Cr(0) with biphenyl at 115°C in the presence of AICI3 allows isolation of bis( -biphenyl)Cr in 20% yield ... 

A serendipitous preparation of arene-metal complexes is the reaction of phenylmag-nesium bromide with chromium trichloride ... 

Polymers containing aryl groups also react efBdently with metal atoms to yield bis(arene)metal(0) complexes within the polymer chain . Thus, poly(methylphenyl-siloxanes) react at 0°C as a liquid with Ti, V, Cr, Mo and W atoms to give high yields of colored bis( / -arene)metal complexes. In contrast Co, Fe and Ni atoms )deld only metal slurries. Similarly, poly(oxyphenylene) and polystyrene (in a solvent) react with V and Cr atoms to yield colored solutions . By adjusting the metal-atom flux, small, polymer-supported Ti and Mo clusters can be prepared . In some cases the com-plexed metal atoms spontaneously migrate through the polymer fluid to form dimers . 

R. L. Pruett, in Preparative Inorganic Reactions , Volume 2, edited by W. L. Jolly (Intersdence, New York, 1965), p. 187. Preparation of cyclopentadienyl and arene metal complexes. 

Many of the known arene metal complexes are shown in Table 18. (a) Preparation... 

Some reactions of bis- /[-arene chromium complexes are shown in Figure 44. The aromatic chemistry of bis-Tc-benzene chromium is rather limited. This is presumably due to the instabilily of the molecule which decomposes under the conditions of the reactions. The metallation reaction mth amyl sodium would appear to open up a route to the preparation of a wide number of derivatives. Few studies have been made of the replacement and substitution reactions of the other bis>arene metal complexes generally, there is little known of the chemistry of the other bis-aiene com-... 

Over the last decade, the chemistry of the carbon-carbon triple bond has experienced a vigorous resurgence [1]. Whereas construction of alkyne-con-taining systems had previously been a laborious process, the advent of new synthetic methodology based on organotransition metal complexes has revolutionized the field [2]. Specifically, palladium-catalyzed cross-coupling reactions between alkyne sp-carbon atoms and sp -carbon atoms of arenes and alkenes have allowed for rapid assembly of relatively complex structures [3]. In particular, the preparation of alkyne-rich macrocycles, the subject of this report, has benefited enormously from these recent advances. For the purpose of this review, we Emit the discussion to cychc systems which contain benzene and acetylene moieties only, henceforth referred to as phenylacetylene and phenyldiacetylene macrocycles (PAMs and PDMs, respectively). Not only have a wide... 

The first arene-transition metal complexes were prepared in the 1950s1314 and it was immediately recognized that the added polarizibility or electron deficiency would promote addition of nucleophiles to the arene ligand. A number of cyclohexadienyl complexes were characterized following nucleophilic addition, but the question of inducing the ipso hydrogen to depart was not answered (equation 1). 

Heterostannenes, preparation and characteristics, 3, 870 Heterosubstituted arenes, metallation, 9, 17 Hexaaryldiplumbanes, preparation, 3, 887 Hexabutyldistannane, preparation, 3, 856 Hexacarbenes, in cobalt(III) complexes, 7, 19 Hexacarbonyl complexes, with molybdenum kinetics and reactivity, 5, 395 photochemistry, 5, 393 solid-support studies, 5, 394 spectroscopic and theoretical studies, 5, 392 Hexadentate iV-substituted triazacyclononane, synthetic applications, 1, 70... 

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