- Mechanistic Dichotomy of Magnesium- and Zinc-Based Germanium Nucleophiles in the C(sp3)?Ge Cross-Coupling with Alkyl Electrophiles
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Robust procedures for two mechanistically distinct C(sp3)?Ge bond formations from alkyl electrophiles and germanium nucleophiles are reported. The germanium reagents were made available as bench-stable solutions by lithium-to-magnesium and lithium-to-zinc transmetalation, respectively. The germanium Grignard reagent reacts with various primary and secondary alkyl electrophiles by an ionic nucleophilic displacement. Conversely, the coupling of the corresponding zinc reagent requires a nickel catalyst, which then engages in radical bond formations with primary, secondary, and even tertiary alkyl bromides. Both methods avoid the regioselectivity issue of alkene hydrogermylation and enable the synthesis of a wide range of functionalized alkyl-substituted germanes.
- Xue, Weichao,Mao, Wenbin,Zhang, Liangliang,Oestreich, Martin
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supporting information
p. 6440 - 6443
(2019/04/08)
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- METHOD FOR PRODUCING 14 GROUP METAL LITHIUM COMPOUND
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PROBLEM TO BE SOLVED: To provide a method for quantitatively producing a group 14 metal lithium compound under a mild condition. SOLUTION: The method for producing a group 14 metal lithium compound represented by formula (4): R4-nMLin comprises reacting a compound represented by formula (1): R4-nMXn and lithium in the presence of a polycyclic aromatic compound represented by formula (2) or formula (3). [In formula (1) and formula (2), R is a hydrocarbon group; M is a metal atom selected from Si, Ge and Sn; X is a halogen atom or R3M- (R and M are the same as mentioned above); and n is 1 or 2] and [R1 is H or a hydrocarbon group; and m is an integer of 0 to 5.] SELECTED DRAWING: None COPYRIGHT: (C)2016,JPOandINPIT
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Paragraph 0072; 0073
(2016/10/31)
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- Stannyl-Lithium: A Facile and Efficient Synthesis Facilitating Further Applications
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We have developed a highly efficient, practical, polycyclic aromatic hydrocarbon (PAH)-catalyzed synthesis of stannyl lithium (Sn-Li), in which the tin resource (stannyl chloride or distannyl) is rapidly and quantitatively transformed into Sn-Li reagent at room temperature without formation of any (toxic) byproducts. The resulting Sn-Li reagent can be stored at ambient temperature for months and shows high reactivity toward various substrates, with quantitative atom efficiency.
- Wang, Dong-Yu,Wang, Chao,Uchiyama, Masanobu
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supporting information
p. 10488 - 10491
(2015/09/28)
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- On the structural diversity of [K(18-crown-6)EPh3] complexes (E = C, Si, Ge, Sn, Pb): Synthesis, crystal structures and NOESY NMR study
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A series of homologous potassium triphenylelement complexes [K(18-crown-6)EPh3] 6a-e of group 14 elements (E = C, Si, Ge, Sn, Pb) was synthesised by alkoxide induced heterolytic cleavage of boron-element compounds. The complexes 6a-e are isolated as storable solids possibly useful as sources of nucleophilic [EPh3]- moieties. The solid state structures of 6a-e were established by X-ray crystal structure determination. Whilst all structures can be described as polymeric chains consisting of alternating [K(18-crown-6)]+ and [EPh3]- units, the interaction within each chain varies systematically with the coordination properties of E. For Si and Ge, classical E-K coordination along with secondary phenyl-K interactions are characteristic, whilst for Sn and Pb, potassium coordination via the phenyl π-system is observed due to inefficient coordination by the free electron pair localised in an 'inert' s-orbital. The carbon derivative is exceptional as the central sp2-hybridised carbon atom gives rise to extensive charge delocalisation and coordination via these partially charged π-systems. A 1H-1H NOESY NMR spectroscopic study in THF-d8 suggests appreciable anion/cation interactions for Si to Pb and hence the presence of contact ion pairs.
- Kleeberg, Christian
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supporting information
p. 8276 - 8287
(2013/07/28)
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- Photochemical Decarbonylation of (α-Arylacyl)triphenylgermane
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(α-Arylacyl)triphenylgermanes were prepared from the corresponding esters with triphenylgermyllithium at room temperature in good yields.Photochemical decarbonylation of (α-arylacyl)triphenylgermanes took place under UV irradiation to quantitatively give
- Kiyooka, Syun-ichi,Shibuya, Tsutomu,Shiota, Fuminori,Fujiyama, Ryoji
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p. 1361 - 1363
(2007/10/02)
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