The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Junichi Yoshida - One of the best experts on this subject based on the ideXlab platform.
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heterocyclization approach for electrooxidative coupling of functional primary Alkylamines with aromatics
ChemInform, 2015Co-Authors: Tatsuya Morofuji, Akihiro Shimizu, Junichi YoshidaAbstract:An effective method for C—H amination of aromatic compounds with functionalized primary Alkylamines via heterocyclization based on the rational reaction design is reported.
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heterocyclization approach for electrooxidative coupling of functional primary Alkylamines with aromatics
Journal of the American Chemical Society, 2015Co-Authors: Tatsuya Morofuji, Akihiro Shimizu, Junichi YoshidaAbstract:A new approach for electrooxidative coupling of aromatic compounds and primary Alkylamines bearing a functional group such as a hydroxyl group and an amino group was developed. The key to the success of the transformation is heterocyclization of functional primary Alkylamines. Treatment of primary Alkylamines bearing a functional group with nitriles or their equivalents gives the corresponding heterocycles. The electrochemical oxidation of aromatic substrates in the presence of the heterocycles followed by chemical reaction under nonoxidative conditions gave the desired coupling products.
Rujin Huang - One of the best experts on this subject based on the ideXlab platform.
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determination of Alkylamines in atmospheric aerosol particles a comparison of gas chromatography mass spectrometry and ion chromatography approaches
Atmospheric Measurement Techniques, 2014Co-Authors: Rujin Huang, W B Li, Y R Wang, Qiyuan Wang, Kinfai Ho, Gehui Wang, X ChenAbstract:Abstract. In recent years low molecular weight Alkylamines have been recognized to play an important role in particle formation and growth in the lower atmosphere. However, major uncertainties are associated with their atmospheric processes, sources and sinks, mostly due to the lack of ambient measurements and the difficulties in accurate quantification of Alkylamines at trace level. In this study, we present the evaluation and optimization of two analytical approaches, i.e., gas chromatography–mass spectrometry (GC-MS) and ion chromatography (IC), for the determination of Alkylamines in aerosol particles. Alkylamines were converted to carbamates through derivatization with isobutyl chloroformate for GC-MS determination. A set of parameters affecting the analytical performances of the GC-MS approach, including reagent amount, reaction time and pH value, was evaluated and optimized. The accuracy is 84.3–99.1%, and the limits of detection obtained are 1.8–3.9 pg (or 0.02–0.04 ng m−3). For the IC approach, a solid-phase extraction (SPE) column was used to separate Alkylamines from interfering cations before IC analysis. 1–2% (v/v) of acetone (or 2–4% (v/v) of acetonitrile) was added to the eluent to improve the separation of Alkylamines on the IC column. The limits of detection obtained are 2.1–15.9 ng (or 0.9–6.4 ng m−3), and the accuracy is 55.1-103.4%. The lower accuracy can be attributed to evaporation losses of amines during the sample concentration procedure. Measurements of ambient aerosol particle samples collected in Hong Kong show that the GC-MS approach is superior to the IC approach for the quantification of primary and secondary Alkylamines due to its lower detection limits and higher accuracy.
Tatsuya Morofuji - One of the best experts on this subject based on the ideXlab platform.
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heterocyclization approach for electrooxidative coupling of functional primary Alkylamines with aromatics
ChemInform, 2015Co-Authors: Tatsuya Morofuji, Akihiro Shimizu, Junichi YoshidaAbstract:An effective method for C—H amination of aromatic compounds with functionalized primary Alkylamines via heterocyclization based on the rational reaction design is reported.
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heterocyclization approach for electrooxidative coupling of functional primary Alkylamines with aromatics
Journal of the American Chemical Society, 2015Co-Authors: Tatsuya Morofuji, Akihiro Shimizu, Junichi YoshidaAbstract:A new approach for electrooxidative coupling of aromatic compounds and primary Alkylamines bearing a functional group such as a hydroxyl group and an amino group was developed. The key to the success of the transformation is heterocyclization of functional primary Alkylamines. Treatment of primary Alkylamines bearing a functional group with nitriles or their equivalents gives the corresponding heterocycles. The electrochemical oxidation of aromatic substrates in the presence of the heterocycles followed by chemical reaction under nonoxidative conditions gave the desired coupling products.
Yoshiyuki Sugahara - One of the best experts on this subject based on the ideXlab platform.
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characterization of bi5nb3o15 by refinement of neutron diffraction pattern acid treatment and reaction of the acid treated product with n Alkylamines
Journal of Solid State Chemistry, 2007Co-Authors: Seiichi Tahara, Nobuhiro Kumada, Akira Shimada, Yoshiyuki SugaharaAbstract:The structure of Bi5Nb3O15 was investigated by refinement of the powder neutron diffraction pattern as well as by structural change through acid treatment and subsequent treatments of an acid-treated product with n-Alkylamines. Rietveld refinement suggests that Bi5Nb3O15 adopts a mixed-layer Aurivillius-related phase structure, [Bi2O2]+[NbO4]+[Bi2O2]+[BiNb2O7] [Pnc 2 (space group No. 30)] with a=2.1011(4)a=2.1011(4), b=0.5473(1)b=0.5473(1) and c=0.5463(1)c=0.5463(1) nm. After the acid treatment of Bi5Nb3O15 with 3 mol/L HCl, a new reflection (at 2.25 nm after drying at room temperature or at 1.89 nm after drying at 120 °C) appeared in the X-ray diffraction (XRD) pattern in addition to the reflections due to Bi5Nb3O15. Upon acid treatment, a part of the Bi ions were lost and essentially no Nb ions were dissolved during acid treatment to give a Bi/Nb molar ratio of 1.4. The TG curves of the acid-treated product showed mass loss (ca. 4 mass%) in the range of 300–600 °C. It was also demonstrated that the particle shapes did not change upon acid treatment. The reaction of the acid-treated product (after drying at room temperature) with n-Alkylamines led to a shift of the newly appearing reflection to a lower angle, and the d-value of the low-angle reflection increased linearly in accordance with the increment of the number of carbon atoms in n-Alkylamines. These results indicate that the [Bi2O2] sheet in Bi5Nb3O15 was partially leached by acid treatment to form a layered compound H4BiNb3O11·xH2O, capable of accommodating n-Alkylamines in the interlayer space, and its anhydrous form, H4BiNb3O11, upon drying. Based on the variation in the interlayer distance upon intercalation of n-Alkylamines into the acid-treated product, the structure of the acid-treated product can be suggested to comprise alternately stacked protonated [BiNb2O7] and [NbO4] sheets, a result consistent with the Rietveld refinement of Bi5Nb3O15.
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intercalation behavior of n Alkylamines into a protonated form of a layered perovskite derived from aurivillius phase bi2srta2o9
Chemistry of Materials, 2003Co-Authors: Yu Tsunoda, Wataru Sugimoto, Yoshiyuki SugaharaAbstract:Intercalation behavior of n-Alkylamines into a protonated form of a layered perovskite, H1.8[Sr0.8Bi0.2Ta2O7], derived from an Aurivillius phase, Bi2SrTa2O9, has been investigated. H1.8[Sr0.8Bi0.2Ta2O7] can accommodate n-Alkylamines (CmHm+1NH2; m = 4, 8, 12, 18) to form intercalation compounds via an acid−base mechanism. The interlayer distance increases to 2.071(2) (m = 4), 2.840(9) (m = 8 ), 3.83(1) (m = 12), and 5.17(2) (m = 18) nm. In contrast, H1.8[Sr0.8Bi0.2Ta2O7] does not form any intercalation compound with pyridine, which is a weaker base, indicating that the protons in H1.8[Sr0.8Bi0.2Ta2O7] are weakly acidic. The IR spectra of the intercalation compounds with n-Alkylamines (m = 12 and 18) clearly show that n-alkyl chains possess an all-trans conformation. A linear relationship is observed between the interlayer distance and the number of carbon atoms in n-alkyl chains, and this corresponds to a bilayer arrangement of the n-alkyl chains with a tilt angle of 60°. Despite the relatively high proton...
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Intercalation of Alkylamines and water into kaolinite with methanol kaolinite as an intermediate
Applied Clay Science, 1999Co-Authors: Yoshihiko Komori, Yoshiyuki Sugahara, Kazuyuki KurodaAbstract:Alkykamines and water were intercalated between the layers of kaolinite by utilizing a kaolinite/methanol intercalation compound as an intermediate. A kaolinite/methanol intercalation compound was synthesized by guest displacement reaction of a kaolinite/N-methylformamide intercalation compound with methanol. The basal spacing increased up to 5.75 nm when octadecylamine was used. It increased linearly with the length of alkyl chains by 0.255 nm per carbon atom, suggesting that the alkylamine molecules in the interlayer space of kaolinite take a bilayer arrangement with their alkyl chains almost perpendicular to the layers of kaolinite. Water molecules were also intercalated into kaolinite by displacement of methanol. The basal spacing of the product was 1.00 nm under wet conditions and 0.85 nm after drying. By using hydrated kaolinite as an intermediate, pyridine molecules were intercalated into kaolinite, thus, the hydrated kaolinite also shows the ability as an intermediate for displacement reactions. These results demonstrate that kaolinite has higher intercalation ability for a wider variety of guest species than previously accepted if appropriate intermediates are used.
Akihiro Shimizu - One of the best experts on this subject based on the ideXlab platform.
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heterocyclization approach for electrooxidative coupling of functional primary Alkylamines with aromatics
ChemInform, 2015Co-Authors: Tatsuya Morofuji, Akihiro Shimizu, Junichi YoshidaAbstract:An effective method for C—H amination of aromatic compounds with functionalized primary Alkylamines via heterocyclization based on the rational reaction design is reported.
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heterocyclization approach for electrooxidative coupling of functional primary Alkylamines with aromatics
Journal of the American Chemical Society, 2015Co-Authors: Tatsuya Morofuji, Akihiro Shimizu, Junichi YoshidaAbstract:A new approach for electrooxidative coupling of aromatic compounds and primary Alkylamines bearing a functional group such as a hydroxyl group and an amino group was developed. The key to the success of the transformation is heterocyclization of functional primary Alkylamines. Treatment of primary Alkylamines bearing a functional group with nitriles or their equivalents gives the corresponding heterocycles. The electrochemical oxidation of aromatic substrates in the presence of the heterocycles followed by chemical reaction under nonoxidative conditions gave the desired coupling products.
