1626-00-2Relevant academic research and scientific papers
Metal cation-methyl interactions in CB11Me12 - salts of Me3Ge+, Me3Sn +, and Me3Pb+
Zharov, Ilya,Weng, Tsu-Chien,Orendt, Anita M.,Barich, Dewey H.,Penner-Hahn, James,Grant, David M.,Havlas, Zdenek,Michl, Josef
, p. 12033 - 12046 (2004)
Oxidation of Me6M2 (M = Ge, Sn) and Me4Pb with the CB11Me12 radical in alkane solvents produced the insoluble salts Me3M+CB11 Me12, - characterized by CP-MAS NMR and EXAFS. The cations interact with methyl groups of CB11Me12- with coordination strength increasing from Pb to Ge. Density functional theory (DFT) calculations for the isolated ion pairs, Me3M+CB11Me 12- (M = Ge, Sn), revealed three isomers with the cation above methyl 2, 7, or 12, and not above a BB edge or a BBB triangle. The interaction has a considerable covalent component, with the cation attempting to perform a backside SE2 substitution on the methyl carbon. In a fourth less favorable isomer the cation is near methyl 1, inclined toward methyl 2, and interacts with hydrogens. DFT atomic charge distributions and plots of the electrostatic potential on the surface of spheres centered at the CB 11H12 and CB11Me12-, icosahedra display the effects of uneven charge distribution within the anion and contradict the common belief that the negative charge of the cage anion is concentrated primarily on the cage boron atoms 7-12; in CB11Me 12-, roughly half is on the cage carbon and the rest on methyls 7-12.
Palladium-Catalyzed Germylation of Aryl Bromides and Aryl Triflates Using Hexamethyldigermane
Komami, Narumi,Matsuoka, Keitaro,Yoshino, Tatsuhiko,Matsunaga, Shigeki
, p. 2067 - 2075 (2018/02/26)
Palladium-catalyzed germylation of aryl bromides and aryl triflates using commercially available hexamethyldigermane is described. Optimized reaction conditions afforded various functionalized aryltrimethylgermanes, including drug-like molecules, in moderate to good yields, demonstrating the versatility of the presented protocols.
General access to para-substituted styrenes
Langle, Sandrine,David-Quillot, Franck,Balland, Alexia,Abarbri, Mohamed,Duchêne, Alain
, p. 113 - 119 (2007/10/03)
A simple and efficient procedure has been developed for the synthesis of organogermanium compounds and styrenes para-substituted with groups containing an atom of the 14th group by one-pot reaction of halogenosilanes, germanes or stannanes, organic halides and magnesium using ultrasound methods.
General access to para-substituted styrenes
Langle, Sandrine,David-Quillot, Franck,Balland, Alexia,Abarbri, Mohamed,Duchêne, Alain
, p. 113 - 119 (2015/03/05)
A simple and efficient procedure has been developed for the synthesis of organogermanium compounds and styrenes para-substituted with groups containing an atom of the 14th group by one-pot reaction of halogenosilanes, germanes or stannanes, organic halides and magnesium using ultrasound methods.
Carbanions as intermediates in the formation of Grignard reagents
Van Klink, Gerard P.M.,De Boer, Henricus J.R.,Schat, Gerrit,Akkerman, Otto S.,Bickelhaupt, Friedrich,Spek, Anthony L.
, p. 2119 - 2135 (2008/10/08)
The formation of reactive carbanions in Grignard reagents was discussed. Inter- and/or intramolecular migrations of organotin and organosilicon groups were also studied. Results showed that the high percentage of rearrangement reactions proves that the anionic species are not located on a minor pathway.
Photochemistry of group 14 1,1,1-trimethyl-2,2,2-triphenyldimetallanes (Ph3MM′Me3; M, M′ = Si, Ge). Direct detection and characterization of silene and germene reactive intermediates
Leigh, William J.,Toltl, Nicholas P.,Apodaca, Paula,Castruita, Madeli,Pannell, Keith H.
, p. 3232 - 3241 (2008/10/08)
The photochemistry of trimethylsilyltriphenylgermane (Ph3GeSiMe3), triphenylsilyltrimethylgermane (Ph3SiGeMe3), and 1,1,1-trimethyl-2,2,2-triphenyldigermane (Ph3GeGeMe3) has been studied in hydrocarbon solution by steady state and laser flash photolysis methods and is compared to previously reported data for the homologous disilane Ph3SiSiMe3. A variety of products are formed upon photolysis of the three compounds in the presence of 2,3-dimethyl-1,3-butadiene or chloroform, but in each case the major ones are derived from M-M′ bond homolysis and dimethyl- or diphenylgermylene extrusion. The trapping products of the 1,3,5-(1-metalla)hexatriene derivatives formed by [1,3]-MMe3 migration into the ortho-position of one of the phenyl rings are formed as well, in yields of 9-30%. While these experiments indicate that germylenes are formed in at least twice the yield of the 1,3,5-(1-metalla)hexatrienes, only the latter and triphenylsilyl or triphenylgermyl radicals can be detected by laser flash photolysis techniques. The metallaenes have been identified on the basis of their time-resolved UV absorption spectra and absolute rate constants for reaction with 2,3-dimethylbutadiene, methanol, acetone, acetic acid, oxygen, and carbon tetrachloride and can be distinguished from germylenes by their lack of reactivity toward triethylsilane and chloroform. Radical formation is shown to result from reaction of the triplet states of these compounds, and a triplet lifetime is estimated for Ph3GeSiMe3 and compared to that of the disilane homologue. The results of time-resolved experiments on other, related compounds are discussed in light of these results.
Generation and reactions of metal-free trialkylgermyl anions from silylgermane and digermane
Mochida, Kunio,Suzuki, Hiroyasu,Nanba, Michihiko,Kugita, Tsuyoshi,Yokoyama, Yasuo
, p. 83 - 88 (2007/10/02)
Metal-free trimethylgermy) anions were prepared by cleavage of the Ge-Si bond of (trimethylsilyl)trimethylgermane and the Ge-Ge bond of hexamethyldigermane with tetrabutylammonium fluoride (TBAF) in hexamethylphosphoric triamide (HMPA).The reactions of metal-free germyl anions produced by a catalytic or one-equivalent amount of TBAF with organic halides carbonyl compounds, and α,β-unsaturated ketones were examined.Keywords: Silicon; Germanium; Germyl anions; Tetrabutylammonium fluoride; Organic halides; Group 14
Photochemical Reactions of Aryl-Substituted Digermanes through a Pair of Organogermyl Radicals
Mochida, Kunio,Wakasa, Masanobu,Sakaguchi, Yoshio,Hayashi, Hisaharu
, p. 1889 - 1895 (2007/10/02)
The photochemical reactions of aryl-substituted digermanes were investigated by trapping experiments and a laser flash photolysis technique.The photolysis of phenylated digermanes resulted in germanium-germanium bond homolysis to give a pair of two germyl radicals.The germyl radicals abstracted a chlorine atom from carbon tetrachloride to give chlorogermanes.The pair of germyl radicals also underwent ipso-substitution, which was a precursor of the germylenes.The mechanism for the photochemistry of phenylated digermenes is discussed.
Photochemical reactions of aryl-substituted catenates of group 4B elements, PhMe2E-E'Me3 (E, E' = Si and Ge). Formation of a radical pair
Mochida, Kunio,Kikkawa, Haruhiko,Nakadaira, Yasuhiro
, p. 9 - 19 (2007/10/02)
Photochemical reactions of phenyl substituted catenates of group 4B elements, PhMe2E-E'Me3 (E, E' = Si and Ge) have been investigated by chemical trapping experiments and laser flash-photolysis.On irradiation, the phenylated group 4B catenate undergoes E-E' bond homolysis to give a pair of radicals (PhMe2E. and Me3E'.).In CCl4, these radicals are converted to the corresponding chlorides by abstraction of a chlorine atom.In a nonhalogenated solvent, the radical pair couples at the ipso-position of the phenyl group of the pairing radical (PhMe2E.) to yield the cor responding diradical.This undergoes either elimination of a divalent species (Me2E:) with concomitant formation of trimethylphenyl group 4B element PhMe3E') or intramolecular 1,2-group 4B element migration to yield group 4B metal-carbon double bonded species.The radical escapes from the solvent cage coupled to the metal atom of the radical to yield the dimetallic product.The reaction path observed is highly dependent on the nature of the group 4B element comprising the phenyl substituted catenate.
