- Structure/property relationships in branched oligogermanes. Preparation of (Me3Ge)3GePh, (Me2ButGe)3GePh, and (Me2PhGe)3GePh and investigation of their properties by spectroscopi
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The three branched oligogermanes (Me3Ge)3GePh, (Me2ButGe)3GePh, and (Me2PhGe)3GePh were synthesized via the hydrogermolysis reaction and were characterized by NMR (1H,
- Komanduri, Sangeetha P.,Shumaker, F. Alexander,Hallenbeck, Sydney A.,Knight, Cody J.,Yoder, Claude H.,Buckwalter, Beth A.,Dufresne, Craig P.,Fernandez, Erico J.,Kaffel, Christopher A.,Nazareno, Ryan E.,Neu, Marshall,Reeves, Geoffrey,Rivard, James T.,Shackelford, Lance J.,Weinert, Charles S.
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p. 104 - 113
(2017/08/02)
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- Microwave-assisted Lewis acid catalysis: Application to the synthesis of alkyl- or arylhalogermanes
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Under microwave irradiation, alkyl- or arylhalogermanes RnGeX4-n (R = Et, Bu, Ph; X = Cl, Br) are obtained by redistribution reactions of R4Ge with GeX4. These experimental conditions permit the synthesis of such compounds in good yield in a few minutes at atmospheric pressure. The direct Friedel-Crafts germylation of benzene and toluene by germanium tetrachloride also has been performed, but yields were low.
- Laurent, Régis,Laporterie, André,Dubac, Jacques,Berlan, Jacques
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p. 2493 - 2495
(2008/10/08)
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- Reactivity of dianionic hexacoordinate germanium complexes toward organometallic reagents. A new route to organogermanes
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Lithium and potassium tris(benzene-1,2-diolato)germanates (2a and 2b, respectively) and potassium tris(butane-2,3-diolato)germanate (3) are easily prepared from GeO2 in quantitative yields. They are very reactive toward organometallic reagents, the reactivity depending on the ligands on the germanium. Complexes 2 react with an excess of Grignard reagent to give the corresponding tetraorganogermanes R4Ge while the less reactive complex 3 leads to the functional triorganogermanes R3GeX. Tetraorganogermanes can also be prepared from complex 2b by reaction with organic bromides in the presence of Mg (Barbier reaction). The influence of Cp2TiCl2 and MgBr2 on the reactivity of Grignard reagents with these complexes was also investigated: in both cases formation of triorganogermanes was favored.
- Cerveau,Chuit,Corriu,Reyé
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p. 1510 - 1515
(2008/10/08)
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- Palladium-catalyzed reduction of acyl chlorides with tributylgermanium hydride
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Tributylgermanium hydride in the presence of Pd(PPh3)4, can reduce acyl chlorides selectively to aldehydes under mild conditions in good yields.
- Geng, Lifeng,Lu, Xiyan
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- REACTIVITY OF ALLYLIC AND VINYLIC SILANES, GERMANES, STANNANES AND PLUMBANES TOWARD SH2' OR SH2 SUBSTITUTION BY CARBON- OR HETEROATOM-CENTERED FREE RADICALS
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Compounds of the type CH2=CHCH2MR3 and (E)-PhCH=CHMR3 (M = Si, Ge, Sn, Pb) were allowed to react with a series of heteroatom-centered radicals (PhY*, Y = S, Se, Te, derived from PhYYPh) and carbon-centered radicals ((CH3)2CH* derived from (CH3)2CHHgCl).We report that alkenylplumbanes and, under forcing conditions, alkenylgermanes undergo SH2 or SH2' substitution of the metal by chain mechanism analogous to those previously reported for alkenylstannanes.Alkenylsilanes are unreactive.Based solely upon product yields, the following trends were observed: The reactivity of the alkenylmetals follow the order metal = Pb > Sn > Ge (> Si).The allylmetals were more reactive then the β-metallostyrenes toward the reactants employed in this study.The chalcogen series PhYYPh exhibits the reactivity order Y = S > Se > Te.
- Light, James P.,Ridenour, Michael,Beard, Lois,Hershberger, James W.
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- METAL-HALOGEN BONDING STUDIES WITH GROUP IV A TRIALKYLMETAL HALIDES
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Halogen redistribution reactions have been found to take place between benzyl bromide or benzyl iodide and the Group IV A silicon, germanium, tin, and lead containing trialkylmetal chlorides.However, for the reactions of the Si, Ge and Sn compounds, a quaternary ammonium halide catalyst was necessary to enable the equilibria to be established at reasonably rapid rates.The equilibrium constants at 50 deg C have been measured for each of these halogen redistributions.They have been found to increase gradually on going down in Group IV A from silicon to lead, being conside rably less than unity in the case of silicon and somewhat greater than unity in the case of lead for both the R3MCl + BzBr and R3MCl + BzI reactions.The ΔG0 values for these equilibria have been calculated, and it is suggested that their differences may be explained in terms of the relative importance of p?-d? contributions to the halogen-metal bonding in the various Group IV A trialkylmetal halide systems.
- Friedrich, Edwin C.,Abma, Charles B.,Vartanian, Paul F.
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p. 203 - 212
(2007/10/02)
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