Transition metals synthesis

Several of the catena-Scx anions have proved to be effective chelating ligands to both main-group and transition metals. Synthesis of the... 

Bums RC, Corbett JD (1982) Heteroatomic polyanions of the post transition metals. The synthesis and stmcture of a copound containing Thallium nonastannide and Thallium Ocatastannide with a novel disorder. J Am Chem Soc 104 2804—2810 Critchlow SC, Corbett JD (1982) Heteropolyatomic anions of the post transition-metals -synthesis and stmcture of the Ditindibismuthide(2-) anion, Sn2Bi2 l Inorg Chem 21 3286-3290... 

H.E. Bryndza u. W. Tam, Chem. Rev. 88, 1163-1188 (1988) Monomeric Metal. .Hydroxides, Alkoxides, and Amides of the Late Transition Metals Synthesis, Reactions, and Thermochemistry". 

Benzene and cyclooctatetraene (COT) derivatives are formed by [2+2+2] and [2+2+2+2] cycloadditions of alkynes. At first the metallacyclopropene 107 and metallacyclopentadiene 108 are formed. Benzene and COT (106) are formed by reductive elimination of the metallacycloheptatriene 109 and the metallacyclononate-traene 110. Formation of benzene by the [2+2+2] cycloaddition of acetylene is catalysed by several transition metals. Synthesis of benzene derivatives from... 

Muller, J.F.K., Kulicke, K.J., Neuburger, M., and Spichty, M., Carbanions siibsliliilcd by transition metals. Synthesis, slriiclure, and configurational restrictions of a lithium titanium phosphonate, Angew. Chem. Int. Ed. Engl., 40, 2890, 2001. 

Hughbanks, T. Corbett, J. D. (1988). Rare-Earth-Metal Iodide Clusters Centered by Transition Metals Synthesis, Structure, and Bonding of R7I12M Compounds (R = Sc, Y, Pr, Gd M = Mn, Fe, Co, Ni), Inorg. Chem. 27, 2022-2026. 

SCS method was used to synthesize single phase Ni nanoparticles to display the possibility of transition metal synthesis using SCS. As presented in Fig 1, the precursor materials are dissolved in water and stirred to get a homogeneous solution. This solution is heated over a hot plate heater to initiate the combustion reaction. Once started, the reaction continues in an auto-thermal mode and no further external heating is reqttired, as the energy released dttring exothermic reaction is sufficient to complete the combustion of entire precursors. The products obtained are crystalline and no calcination is reqttired. 

K. Kudoh, T. Okamoto and S. Yamaguchi, Reactions of fused polycyclic 1,2-dithiins with transition metals synthesis of heteroacenes via desulfurization, Organometallics, 25, 2374-2377 (2006). 

Bryndza HE, Tam W (1988) Monomeric metal hydroxides, alkoxides, and amides of the late transition metals synthesis, reactions, and thermochemistry. Chem Rev 88 1163-1185... 

Muller JFK, Kulicke KJ, Neuburger M, Spichty M (2001) Carbanions substituted by transition metals synthesis, structure, and configurational restrictions of a lithium titanium phosphonate. Angew Chem Int Ed 12 2890-2893. doi 10.1002/1521-3773(20010803) 40 15<2890 AID-ANIE2890>3.0.CO 2-T... 

Wallace C H 1998 The rapid solid-state synthesis of group III and transition metal nitrides at ambient and high pressures PhD Dissertation University of California, Los Angeles... 

Perego G, Millini R and Bellussi G 1998 Synthesis and characterization of molecular sieves containing transition metals in the framework Moiecuiar Sieves Science and Technoiogy vol 1, ed FI G Karge and J Weitkamp (Berlin ... 

P. J. Harrington, Transition Metals in Total Synthesis, Wiley, New York, 1990... 

F. J. McQuillin, Transition Metals Organornetallics for Organic Synthesis, Cambridge University Press, Cambridge, 1991. 

The development of methods for aromatic substitution based on catalysis by transition metals, especially palladium, has led to several new methods for indole synthesis. One is based on an intramolecular Heck reaction in which an... 

Addition of HCN to unsaturated compounds is often the easiest and most economical method of making organonitnles. An early synthesis of acrylonitrile involved the addition of HCN to acetylene. The addition of HCN to aldehydes and ketones is readily accompHshed with simple base catalysis, as is the addition of HCN to activated olefins (Michael addition). However, the addition of HCN to unactivated olefins and the regioselective addition to dienes is best accompHshed with a transition-metal catalyst, as illustrated by DuPont s adiponitrile process (6—9). 

Apphcations of ultrasound to electrochemistry have also seen substantial recent progress. Beneficial effects of ultrasound on electroplating and on organic synthetic apphcations of organic electrochemistry (71) have been known for quite some time. More recent studies have focused on the underlying physical theory of enhanced mass transport near electrode surfaces (72,73). Another important appHcation for sonoelectrochemistry has been developed by J. Reisse and co-workers for the electroreductive synthesis of submicrometer powders of transition metals (74). 

In addition to the processes mentioned above, there are also ongoing efforts to synthesize formamide direcdy from carbon dioxide [124-38-9J, hydrogen [1333-74-0] and ammonia [7664-41-7] (29—32). Catalysts that have been proposed are Group VIII transition-metal coordination compounds. Under moderate reaction conditions, ie, 100—180°C, 1—10 MPa (10—100 bar), turnovers of up to 1000 mole formamide per mole catalyst have been achieved. However, since expensive noble metal catalysts are needed, further work is required prior to the technical realization of an industrial process for formamide synthesis based on carbon dioxide. 

Although a few simple hydrides were known before the twentieth century, the field of hydride chemistry did not become active until around the time of World War II. Commerce in hydrides began in 1937 when Metal Hydrides Inc. used calcium hydride [7789-78-8J, CaH2, to produce transition-metal powders. After World War II, lithium aluminum hydride [16853-85-3] LiAlH, and sodium borohydride [16940-66-2] NaBH, gained rapid acceptance in organic synthesis. Commercial appHcations of hydrides have continued to grow, such that hydrides have become important industrial chemicals manufactured and used on a large scale. 

Soluble and weU-characterized polygermane homopolymers, (R Ge), and their copolymers with polysdanes have been prepared by the alkaH metal coupling of diorgano-substituted dihalogermanes (137—139), via electrochemical methods (140), and by transition-metal catalyzed routes (105), as with the synthesis of polysdanes. 

In another process for the synthesis of PPS, as well as other poly(arylene sulfide)s and poly(arylene oxide)s, a pentamethylcyclopentadienylmthenium(I) TT-complex is used to activate -dichlorobenzene toward displacement by a variety of nucleophilic comonomers (92). Important facets of this approach, which allow the polymerization to proceed under mild conditions, are the tremendous activation afforded by the TT-coordinated transition-metal group and the improved solubiUty of the resultant organometaUic derivative of PPS. Decomplexation of the organometaUic derivative polymers may, however, be compHcated by precipitation of the polymer after partial decomplexation. 

Studies of the synthesis of quiaolines usiag transition-metal catalysts and nonacidic conditions (55) have determined that mthenium(III) chloride is the most effective of a wide range of catalysts. The reaction between nitrobenzene and 1-propanol or 1-butanol gives 65 and 70% yields of 2-ethyl-3-methylquiQoline [27356-52-1] and 3-ethyl-2-propylquiQoline, respectively. 

One of the most exciting discoveries related to quinone/hydroquinone chemistry is thek synthesis by biosynthetic routes (12,13). Using bacterial enzymes to convert D-glucose [50-99-7] (7) to either 1,2- or l,4-ben2enediol allows the use of renewable raw material to replace traditional petrochemicals. The promise of reduced dependence on caustic solutions and the use of transition-metal catalysts for thek synthesis are attractive in spite of the scientific and economic problems still to be solved. 

CyclopentadienylthaHium and its alkylated derivatives are used in the synthesis of metallocenes (qv) and other transition-metal cyclopentadienyl complexes (29). 

H. Alper, ed.. Transition Metal Organometallics in Organic Synthesis, Academic Press, Inc., New York, 1976. 

C. W. Bird, Transition Metal Intermediates in Organic Synthesis, Logos Press, London, UK, 1968. 

The performance of many metal-ion catalysts can be enhanced by doping with cesium compounds. This is a result both of the low ionization potential of cesium and its abiUty to stabilize high oxidation states of transition-metal oxo anions (50). Catalyst doping is one of the principal commercial uses of cesium. Cesium is a more powerflil oxidant than potassium, which it can replace. The amount of replacement is often a matter of economic benefit. Cesium-doped catalysts are used for the production of styrene monomer from ethyl benzene at metal oxide contacts or from toluene and methanol as Cs-exchanged zeofltes ethylene oxide ammonoxidation, acrolein (methacrolein) acryflc acid (methacrylic acid) methyl methacrylate monomer methanol phthahc anhydride anthraquinone various olefins chlorinations in low pressure ammonia synthesis and in the conversion of SO2 to SO in sulfuric acid production. 

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