- Reactions of nucleophilic reagents with dianionic hexacoordinated germanium complexes: A new convenient route to functional organogermanes from germanium dioxide
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Tetraorganogermanes and triorganogermanes can be prepared in two steps from GeO2: the preparation of the anionic hexacoordinated germanium complexes followed by reaction of these with Grignard reagents to give the organogermanes.
- Cerveau,Chuit,Corriu,Reye
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- Untersuchungen von Diiodogermylen und Triphenylphosphindiiodogermylen und die Kristallstruktur von Triphenylphosphindiiodogermylen
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Reaktivitaeten und chemische Eigenschaften von Diiodogermylen und Triphenylphosphindiiodogermylen wurden durch ihre Reaktionen mit Organolithium-Verbindungen oder Butadienen untersucht.Die Kristallstruktur von Triphenylphosphindiiodogermylen wurde roentgenographisch aufgeklaert.
- Inoguchi, Yoshio,Okui, Shuko,Mochida, Kunio,Itai, Akiko
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- Synthesis of Bis(pentafluoroethyl)germanes
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The chemistry of bis(pentafluoroethyl)germanes (C2F5)2GeX2 is presented. The synthesis of such species requires Br2GePh2, wherein the phenyl substituents function as suitable protecting groups. After treatment with two equivalents of LiC2F5, (C2F5)2GePh2 is produced. The replacement of the phenyl rings is smoothly effected by gaseous HBr or HCl in the presence of a Lewis acidic catalyst. The trigermoxane [(C2F5)2GeO]3 results from the reaction of (C2F5)2GeBr2 with Ag2CO3. Its crystalline 1,10-phenanthroline adduct was fully characterised by X-ray diffraction. The combination of (C2F5)2GeBr2 with Bu3SnH gave rise to the formation of (C2F5)2GeH2.
- Pelzer, Stefanie,Neumann, Beate,Stammler, Hans-Georg,Ignat'ev, Nikolai,Hoge, Berthold
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- Preliminary communication. Kinetic spectroscopy of diphenylgermylene Ph2Ge following laser flash photolysis of bis(trimethylsilyl)diphenylgermane (Me3Si)2GePh2
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A transient, λmax 445 nm, was observed in the 266 nm laser flash photolysis of cyclohexane solutions of (Me3Si)2GePh2, and rate constants were recorded for its disappearance in the presence of various trapping agents.The reactivity profile is in accord with the identification of the carrier as diphenylgermylene Ph2Ge, that dimerizes to tetraphenyldigermene Ph2Ge=GePh2, λ7max3 320 nm.
- Konieczny, Stanislaw,Jacobs, S. Joshua,Wilking, Janet K. Braddock,Gaspar, Peter Paul
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- Pd/Ni-Catalyzed Germa-Suzuki coupling via dual Ge-F bond activation
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Pd/Ni → Ge-F interactions supported by phosphine-chelation were found to trigger dual activation of Ge-F bonds under mild conditions. This makes fluoro germanes suitable partners for catalytic Ge-C cross-coupling and enables Germa-Suzuki reactions to be a
- Kameo, Hajime,Mushiake, Akihiro,Isasa, Tomohito,Matsuzaka, Hiroyuki,Bourissou, Didier
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supporting information
p. 5004 - 5007
(2021/05/28)
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- Reaction of germanes and digermanes with triflic acid: The route to novel organooligogermanes
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Novel germanium containing triflates were prepared from the reactions of trifluoromethanesulfonic acid with tetraphenylgermane (1) and digermanes (Ph3GeGeMe3 (4), Ph3GeGePh3 (5)). The improved procedures for synthesis of known organogermanium compounds (Ph4Ge (1), Ph3GeCl (2), Ph3GeGeMe3 (4), Ph3GeGePh3 (5)) were also presented. The crystal structure of Ph3GeOTf (6) and Ph2Ge(OTf)Ge(OTf)Ph 2 (7) was studied by X-ray analysis. In 7 each germanium atom is pentacoordinated due to intramolecular interaction with O atom of the neighboring triflate group.
- Zaitsev, Kirill V.,Kapranov, Andrey A.,Oprunenko, Yuri F.,Churakov, Andrei V.,Howard, Judith A.K.,Tarasevich, Boris N.,Karlov, Sergey S.,Zaitseva, Galina S.
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p. 207 - 213
(2012/03/26)
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- Thermal reactivity of cis- and trans-bis(triphenylgermyl)bis(tertiary phosphine)platinum(II)
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The complex cis-Pt(Ph3Ge)2(PMe2Ph)2 underwent smooth isomerization to give the trans-isomer at room temperature via an associative five-coordinated intermediate. Thermodynamic parameters and activation energy for the cis to trans isomerization were obtained, ΔH# = 105 kJ mol-1, ΔS# = 12.5 J mol-1 K-1, and Ea = 107 kJ mol-1, respectively. Heating of trans-Pt(Ph3Ge)2(PMe2Ph)2 at 50 °C for 36 days produced trans-PtPh(Ph3Ge)(PMe2Ph)2 followed by the formation of trans-PtPh2(PMe2Ph)2, Pt(PMe2Ph)4, and Ph4Ge finally via elimination of the phenyl group from Ph3Ge ligand with liberation of the Ph2Ge unit and subsequent reductive elimination of the remaining Ph3Ge ligand at 80 °C for 1 month.
- Mochida, Kunio,Fukushima, Takashi,Suzuki, Michiko,Hatanaka, Wakako,Takayama, Mariko,Usui, Yoko,Nanjo, Masato,Akasaka, Kuniyoshi,Kudo, Takako,Komiya, Sanshiro
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p. 395 - 401
(2008/02/06)
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- Reactions of organochlorosilanes with chloro-and organogermanes in the presence of aluminum chloride
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The effect of substituents at the silicon and germanium atoms in reactions of organochlorosilanes with chloro-and organogermanes in the presence of aluminum chloride was studied. The only occurring process is the exchange of the chlorine atoms at Ge for the phenyl groups from Si; an increase in the number of methyl groups or chlorine atoms at Si promotes formation of phenyltrichlorogermane, and an increase in the number of phenyl groups or replacement of the chlorine atom at the Si atom by hydrogen leads to the formation of di-and triphenylchlorogermanes. Neither phenyl nor other radicals are transferred back from Ge to Si in the course of reactions of phenylgermanes with methylchlorosilanes in the presence of aluminum chloride; the only occurring processes are the exchange of the phenyl or methyl radicals bonded to Ge for the Cl atom bonded to Al and the disproportionation of phenylchlorogermanes. Nauka/Interperiodica 2006.
- Zhun,Sbitneva,Polivanov,Chernyshev
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p. 1564 - 1570
(2008/02/09)
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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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- UEBER POLYGERMANE XIV. POLYGERMANE ALS NEBENPRODUKTE DER GRIGNARD-REAKTION VON PhMgBr MIT GeCl4
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The synthesis of GePh4 and Ge2Ph6 by Grignard reaction in THF or ether/toluene leads to the by-products Ge3Ph8 (up to 11 percent) and Ge4Ph10 (up to 18 percent) which is dependant on using an excess of Mg.A quantitative analysis of the resulting products by HPLC and a semipreparative separation by column, flash, and HPL chromatography is described.The crystal structures of Ge3Ph8 (R=0.075) and Ge4Ph10*2C6H6 (R=0.054) have been determined.Ge4Ph10 has Ci symmetry and both chain conformations are well staggered (49-70 deg for Ge3Ph8, 53-66 deg for Ge4Ph10).The Ge-Ge distances and Ge-Ge-Ge angles are 244 pm and 121 deg (Ge3Ph8), and 246 pm and 118 deg (Ge4Ph10).
- Roller, Stefan,Simon, Dietolf,Draeger, Martin
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- POLYGERMANES PRECURSEURS D'ESPECES DU GERMANIUM A COORDINNANCE NON USUELLE
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Several thermal or photochemical α-elimination reactions of functional polygermanes lead to germylenes, R2Ge.Photolysis of polygermanes, cyclopolygermanes and polygermylmercury compounds and also hydrogen abstraction from various organohydropolygermanes using t-BuO., lead to the formation of polymetallated chains containing one or two germanium-centered radicals.These polygermyl radicals give germylenes, R2Ge, germanium centered radicals Ge., α-digermyl diradicals (or digermenes) Ge.-Ge. or Ge=Ge> and β- or γ-polygermyl diradicals via ahomolytic monoelectronic α-elimination process.In some cases the formation of α-digermyl diradicals or digermenes can also be seen as occuring through dimerization of germylenes but with lower yields.All these intermediates have been characterized by several trapping reactions with dimethyl disulfide, 2,3-dimethylbutadiene or biacetyl.
- Riviere, P.,Castel, A.,Satge, J.,Guyot, D.
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p. 193 - 206
(2007/10/02)
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- ASSISTANCE NUCLEOPHILE DANS DES REACTIONS DE REDUCTION D'ORGANOHALOGENO- ET HALOGENO-GERMANES PAR DES REDUCTEURS DOUX R3M(IVB)-H ET RCHO: GERMYLANIONS, DERIVES FONCTIONNELS DU GERMANIUM
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Catalytic activity of nuclophiles such as tertiary amines and diazo derivatives in the reduction of halogermanes by means of gentle reductive agents, such as R3M(IVB)-H or RCHO, has been shown.In the particular case of enolisable aldehyde, a competition between nucleophilic substitution at the metal and germanium-halogen bond reduction has been observed.Transposition of enoxygermanes formed through the substitution process, leads to β-germylaldehydes.
- Castel, A.,Riviere, P.,Satge, J.
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p. 137 - 146
(2007/10/02)
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