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The stereoselective glycosylation of alcohols and their silyl ethers has been achieved using O-alkyl-, O-acyl-, and acetal-protected glycosyl fluorides of the pyranose and furanose series and boron trifluoride etherate in CH2Cl2. 相似文献
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An efficient, high-yielding and scalable procedure for the regioselective 3-acylation of indoles with anhydrides promoted by boron trifluoride etherate under mild conditions was reported. This novel protocol provided a simple way to prepare 3-(benzofuran-2-yl) indole in three steps. 相似文献
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Junlong Xiong Shiqiang Yan Ning Ding Wei Zhang Yingxia Li 《Journal of carbohydrate chemistry》2013,32(3):184-192
An efficient and convenient method for the selective cleavage of terminal acetonides is described. Treatment of terminal acetonides in the presence of a wide range of functional groups with silica-supported boron trifluoride as a catalyst furnished the corresponding diols in 82–95% yield under ultrasound irradiation conditions. The acid-labile p-methoxybenzyl group as a protecting group remained intact under the conditions employed to the present deprotection condition. 相似文献
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在新型混合电解质——乙酸含体积比26%的三氟化硼乙醚和5%的分子量为400的聚乙二醇中直接氧化咔唑制得高质量的聚咔唑膜,导电率为10-2 S·cm-1。在该体系中,咔唑的起始氧化电位相对于饱和甘汞电极只有0.89 V,远低于在含0.1 mol·L-1四氟化硼四丁基铵的乙腈溶液中的1.36V(相对于饱和甘汞电极)。从该体系中获得的聚咔唑膜具有良好的电化学性质和热稳定性,可以部分溶于二甲基亚砜、四氢呋喃等强极性溶剂。荧光光谱表明该体系中获得的聚咔唑膜是一种良好的蓝光发射材料。红外、核磁波谱和理论量子化学计算结果表明,咔唑的电化学聚合主要发生在3,6位。据我们所知,这是利用乙酸三氟化硼乙醚混合电解质进行电化学聚合的首次报道。 相似文献
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在三氟化硼乙醚(BFEE)-浓硫酸混合电解质体系中直接氧化9,10-二氢化菲获得了高质量聚(9,10-二氢化菲)膜, 其电导率为3.8×10-1 S/cm. 9,10-二氢化菲在BFEE+10%浓硫酸体系中的起始氧化电位为0.93 V vs. SCE, 远低于其在乙腈+0.1 mol/L Bu4NBF4溶液中的起始氧化电位(1.75 V vs. SCE). 在BFEE+10%浓硫酸体系中获得的聚(9,10-二氢化菲)膜具有良好的电化学性质. 聚合物部分溶于二甲基亚砜、四氢呋喃、氯仿等极性溶剂. FT-IR和量化计算表明聚合反应主要发生在2, 7位或者3, 6位. 荧光光谱和热重分析表明聚合物是一种良好的蓝色荧光材料且具有良好的热稳定性. 相似文献
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研究了三氟化硼乙醚(BF3·OEt2)催化2-(N-取代氨基甲酰基甲基氨基)苯甲醇与醛的反应,发展了合成取代3,1-苯并噁嗪类化合物的方法,通过该方法合成了一系列新型结构的1-(氨基甲酰基甲基)-2-烃基-3,1-苯并噁嗪类化合物。 对于这类反应BF3·OEt2比三甲基氯硅烷(TMSCl)和四氯化锡(SnCl4)的普适性更广,它能有效催化这类反应,而后二者却不能。 探讨了TMSCl和SnCl4不能催化2-(N-取代氨基甲酰甲基氨基)苯甲醇与醛反应的原因。 相似文献
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《合成通讯》2013,43(18):3399-3408
Abstract Tetralones 3 and 9 on treatment with a mixture of boron trifluoride etherate and acetic anhydride underwent molecular transformations yielding the fully aromatized products 6 and 10, respectively, Oxidation of dimethoxy tetralin 13 with chromic acid and acetic acid afforded 6‐methoxy‐α‐tetralone 12. 相似文献
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High quality poly(5-cyanoindole) (P5CI) films were electrosynthesized by direct anodic oxidation of 5-cyanoindole on stainless steel sheet in the mixed electrolytes of boron trifluoride diethyl etherate (BFEE) and diethyl ether (EE) (by volume 1:1) + 0,05 mol L^-1 Bu4NBF4. The film formed can be peeled off the electrode into freestanding films, The addition of EE into BFEE can improve the solubility of monomer. P5CI films obtained from this medium showed excellent electrochemical behavior with conductivity of 10^-2 S cm^-1, Structural studies showed that the polymerization of 5-cyanoindole occurred at the 2,3 position. As-formed P5CI films were thoroughly soluble in strong polar organic solvent dimethyl sulfoxide (DMSO) while partly soluble in tetrahydrofuran (THF) or acetone. Fluorescence spectral studies indicated that P5CI was a good blue-ight emitter. 相似文献
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Polystyrene, cross-linked with 7.8% of divinylbenzene, formed a stable complex in chloroform with boron trifluoride containing 0.11% of boron, while cross-linked polystyrene-4-vinylpyridine resins containing 2–2.5% of pyridine rings formed a stable complex with boron trifluoride, containing 1.04% of boron. Both complexes catalyze conversions of aromatic aldehydes, ketones, and acids with alcohols into corresponding acetals, cyclic ketals, and esters; diphenylmethanol converts into ether. The structure of the alcohol plays an important role, with conversions decreasing in the order 1-butanol, 2-butanol, tert-butanol. Both complexes are very stable and in most cases more reactive than the cross-linked polystyrene-A1C13 complex. 相似文献
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V. A. Gilyarov E. I. Matrosov A. N. Nesmeyanov 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract Alkyliminotrialkylphosphoranes form stable complexes with BF3 which structures have not been studied earlier. It is possible that these complexes are formed at the first stage of imide-amide rearrangement under action of the BF3 etherate. As the adducts cannot be isolated, we decided to study the stable BF3 adducts with phenyliminotriphenylphosphorane (la), p-fluorophenyliminotriphenyl-phosphorane (lb) and benzyliminotriphenylphosphorane (Ic), all being crystalline compounds. 相似文献
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Anthony J. Arduengo III Fredric Davidson Roland Krafczyk William J. Marshall Reinhard Schmutzler 《Monatshefte für Chemie / Chemical Monthly》2000,25(5):251-265
Synthesis, characterization, and solid state X-ray crystallographic structures for 12-Pn-6 complexes derived from carbene 4,5-dichloro-1,3-dimesitylimidazol-2-ylidene and phosphorus, arsenic, or antimony pentafluoride
are reported. The adducts show octahedral geometries at the pnictogen centers with C-Pn bond distances of 189.8 (P), 199.9 (As), and 217.5 (Sb) pm. The structures are those of internal zwitterions with imidazolium
ion character in the heterocyclic ring and a pentafluoropnictanide anion bonded to C2. Adducts of BF3 with 1,3-dimesitylimidazol-2-ylidene and 4,5-dichloro-1,3-dimesitylimidazol-2-ylidene are also reported for comparison. Although
the reactivity of chlorinated and non-chlorinated carbenes varies considerably, the spectroscopic and structural properties
of analogous adducts are remarkably similar. 相似文献
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Anthony J. Arduengo III Fredric Davidson Roland Krafczyk William J. Marshall Reinhard Schmutzler 《Monatshefte für Chemie / Chemical Monthly》2000,131(3):251-265
Summary. Synthesis, characterization, and solid state X-ray crystallographic structures for 12-Pn-6 complexes derived from carbene 4,5-dichloro-1,3-dimesitylimidazol-2-ylidene and phosphorus, arsenic, or antimony pentafluoride
are reported. The adducts show octahedral geometries at the pnictogen centers with C-Pn bond distances of 189.8 (P), 199.9 (As), and 217.5 (Sb) pm. The structures are those of internal zwitterions with imidazolium
ion character in the heterocyclic ring and a pentafluoropnictanide anion bonded to C2. Adducts of BF3 with 1,3-dimesitylimidazol-2-ylidene and 4,5-dichloro-1,3-dimesitylimidazol-2-ylidene are also reported for comparison. Although
the reactivity of chlorinated and non-chlorinated carbenes varies considerably, the spectroscopic and structural properties
of analogous adducts are remarkably similar.
Received September 6, 1999. Accepted (revised) October 20, 1999 相似文献
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Biswanath Das Cheruku Ravindra Reddy Chava Sindhu Duddukuri Nandan Kumar Martha Krishnaiah 《Helvetica chimica acta》2011,94(2):289-292
[(Tosylamino)alkyl]naphthalenols have efficiently been synthesized by nucleophilic addition of naphthalen‐2‐ol with N‐tosyl imines (derived from both aromatic and aliphatic aldehydes) in the presence of BF3?OEt2 as a catalyst at room temperature. The products are formed within 5–9 h in high yields (72–91%). 相似文献
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