- Alkali metal and ammonium cation-arene interactions with tetraphenylborate anion
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Sodium, potassium, rubidium, caesium, ammonium and tetramethylammonium tetraphenylborates were studied by both positive and negative ion electrospray mass spectrometry. An affinity order of Cs+ > Rb+ > K+ Na+ was obtained. The results obtained were compared with both calculations and solid-state structures, where available. The previously reported high affinity of caesium for tetraphenylborate concluded from NMR experiments was confirmed for the gas phase. The affinity does not appear to result from steric effects and a cation-pi interaction seems likely. In the positive ion mode, a unique acetonitrile complex of NaBPh4 was observed.
- Li, Ruiqiong,Winter, Rudolph E.K.,Kramer, Joseph,Gokel, George W.
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Read Online
- Preparation method of tetraphenylborate
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The invention discloses a preparation method of tetraphenylborate. Sodium tetraphenylborate reacts with a quaternary salt compound under the synergistic effect of water and an organic solvent to prepare a tetraphenylborate product, and the organic solvent is an organic solution which can dissolve the quaternary salt compound and does not participate in the reaction. According to the method, the process of almost quantitatively reacting sodium tetraphenylborate with the quaternary salt compound in a mixed reaction system consisting of water and an organic solution to obtain an organic quaternary tetraphenylborate product is realized, the product purity is high, and the byproduct sodium salt is completely dissolved in water, so that interference byproducts are avoided, the method is suitable for efficient and high-purity large-scale preparation and production of organic tetraphenylborate.
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Paragraph 0032
(2021/06/13)
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- An Umpolung Approach to Alkene Carboamination: Palladium Catalyzed 1,2-Amino-Acylation, -Carboxylation, -Arylation, -Vinylation, and -Alkynylation
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Conventional approaches to Pd-catalyzed alkene 1,2-carboamination rely upon the combination of a nucleophilic nitrogen-based component and an internal C-based or external oxidant. In this study, we outline an umpolung approach, which is triggered by oxidative initiation at an electrophilic N-based component and employs "standard" organometallic nucleophiles to introduce the new carbon-based fragment. Specifically, oxidative addition of a Pd(0)-catalyst into the N-O bond of O-pentafluorobenzoyl oxime esters generates imino-Pd(II) intermediates, which undergo 5-exo cyclization with sterically diverse alkenes. The resultant alkyl-Pd(II) intermediates are intercepted by organometallic nucleophiles or alcohols, under carbonylative or noncarbonylative conditions, to provide 1,2-carboamination products. This approach provides, for the first time, a unified strategy for achieving alkene 1,2-amino-acylation, -carboxylation, -arylation, -vinylation, and -alkynylation. For carbonylative processes, orchestrated protodecarboxylation of the pentafluorobenzoate leaving group underpins reaction efficiency. This process is likely a key feature in related Narasaka-Heck cyclizations and accounts for the efficacy of O-pentafluorobenzoyl oxime esters in aza-Heck reactions of this type. (Chemical Equation Presented).
- Faulkner, Adele,Scott, James S.,Bower, John F.
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supporting information
p. 7224 - 7230
(2015/06/25)
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- Zintl anions from the extraction of zintl phases with non-amine solvents: Isolation of (Me4N)4Sn9, [K(HMPA)2]4Sn9, and K4SnTe4 and structural characterization of (Bu4N)2Mx (M = Te, x = 5; M = Se, x = 6; M = S, x = 6)
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Polyatomic main-group anions like Sn94-, Te52-, Se62-, S62-, and SnTe44- have been isolated without the use of cryptate ligands. The polychalcogenides (Bu4N)2Mx (where M = Te, x = 5; M = Se, x = 6; M = S, x = 6; Bu = n-C4H9) are obtained by the aqueous extraction of binary alkali-metal/main-group alloys in the presence of Bu4NBr. These polychalcogenides are isomorphous and have been structurally characterized by X-ray crystallography. The nonastannide(4-) anion has been isolated both as the tetrakis(tetramethylammonium) compound, [(CH3)4N]4Sn9, and as the HMPA (hexamethylphosphoric triamide) solvate, [K(HMPA)2]4Sn9. Both compounds are somewhat thermally unstable at 25 °C. The compound K4SnTe4 has been isolated by the aqueous extraction of ternary K/Sn/Te alloys.
- Teller, Raymond G.,Krause, Larry J.,Haushalter, Robert C.
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p. 1809 - 1812
(2008/10/08)
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