- Systematic study of synthesizing various heteroatom-substituted rhodamines from diaryl ether analogues
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The dye rhodamine, as the most popular scaffold to construct fluorescent labels and probes, has been explored extensively on its structure-fluorescence relationships. Particularly, the replacement of the oxygen atom in the 10th position with heteroatoms obtained various new rhodamines with improved photophysical properties, such as brightness, photostability, red-shifted emission and fluorogenicity. However, the applications of heteroatom-substituted rhodamines have been hindered by difficult synthetic routes. Herein, we explored the condensation strategy of diaryl ether analogues and o-tolualdehyde to synthesize various heteroatom-substituted rhodamines. We found that the electron property and steric effect in the rhodamine 10th position determined the synthetic yield. It's concluded that this condensation method was more suitable for the synthesis of heteroatom-substituted rhodamines with small or electron-donating groups like rhodamine, S-rhodamine and Si-rhodamine. We hope these results will benefit the design and synthesis of heteroatom-substituted rhodamines.
- Deng, Fei,Huang, Chunfang,Huang, Wei,Liu, Limin,Qiao, Qinglong,Xu, Zhaochao
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- Palladium-catalyzed one-step synthesis of symmetrical diaryl sulfones from aryl halides and a sulfur dioxide surrogate
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A convenient method for the one-step synthesis of symmetrical diaryl sulfones from aryl halides has been developed. A keystone of the method is the use of K2S2O5, which can be easily and safely handled, as a sulfur dioxide surrogate. The palladium catalyst bearing P(t-Bu)3 as a ligand enables formation of the desired sulfones without significant formation of byproducts.
- Tanaka, Hiromichi,Konishi, Hideyuki,Manabe, Kei
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supporting information
p. 760 - 763
(2019/08/02)
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- Catalytic hydrogenation of sulfur-containing nitrobenzene over Pd/C catalysts: In situ sulfidation of Pd/C for the preparation of PdxSy catalysts
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The preparation of supported palladium sulfides catalysts has attracted much attention due to their good sulfur-resistant properties in the hydrogenation of sulfur-containing compounds. In this work, we unambiguously demonstrated that Pd/C catalyst could be in situ sulfided by organic sulfur-containing reactant molecules and the sulfidation was highly dependent on temperature. The in situ sulfidation of Pd/C catalyst was composed of a reaction of Pd with the sulfur derived from the cleavage of C-S bond of sulfur-containing reactant molecules, followed by a transformation to PdxSy at high temperatures (around 120 °C). The sulfided Pd/C catalyst could be used for at least 18 recycles without a significant loss in its activity during the hydrogenation of sulfur-containing nitrobenzene at 180 °C with 3 MPa H2, which could be attributed to the stable presence of Pd4S and Pd16S7.
- Zhang, Qunfeng,Xu, Wei,Li, Xiaonian,Jiang, Dahao,Xiang, Yizhi,Wang, Jianguo,Cen, Jie,Romano, Stephen,Ni, Jun
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- Synthesis, characterization, and quantum chemical calculation studies on 3-(3-nitrophenylsulfonyl)aniline
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A novel partially reduced polynitro aromatic compound, 3-(3- nitrophenylsulfonyl)aniline (III), was found during the catalytic transfer hydrogenation of 3,3′-sulfonylbis(nitrobenzene) (I) to 3,3′-sulfonyldianiline (II). III was identified and characterized by elemental analysis, IR, 1H NMR, and X-ray single crystal diffraction. The optimized geometries of III calculated by DFT-B3LYP/6-31G and HF/6-31G closely resemble the crystal structure. The frontier orbital gap and the electrostatic potential isosurface map of III were calculated and compared with those of I. HF/6-31G method is better than DFT-B3LYP/6-31G method to predict the vibrational frequencies by the comparisons between the calculated results and the experimental data. The present study of III, in general, may lead to the better understanding of the mechanisms and intermediates of the reduction of polynitro aromatic compounds, especially the nitro groups at the different aromatic rings, and may also help in designing and synthesizing new partial reduction products for technological applications.
- Li, Yi,Zhang, Haibao,Liu, Yuanyuan,Li, Fangshi,Liu, Xiaoning
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experimental part
p. 110 - 116
(2011/09/13)
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- Fluorimetric and prototropic studies on the inclusion complexation of 3,3′-diaminodiphenylsulphone with β-cyclodextrin and its unusual behavior
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The photophysical and photoprototropic properties of 3,3′- diaminodiphenylsulphone (3DADPS) in aqueous β-cyclodextrin (β-CDx) solution have been investigated using absorption and fluorescence spectral techniques. β-CDx forms 1:1 inclusion complex with 3DA
- Enoch, Muthu Vijayan,Rajamohan, Rajaram,Swaminathan, Meenakshisundaram
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body text
p. 473 - 477
(2010/12/19)
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- Inkjet ink
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The invention relates to a method for manufacturing an inkjet ink including a polyamic acid (A), including a step of at least reacting one or more compounds selected from the group of a monoamine (a3) and a compound having one acid anhydride group (a4) with a compound having two or more acid anhydride groups (a1) and a diamine (a2).
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- Effect of synthesis conditions on formation of partially crystalline polyimides based on meta-substituted binuclear diamines
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Partially crystalline polyimides were prepared from 3,3′,4,4′-benzophenonetetracarboxylic acid and meta-substituted binuclear diamines. The products exhibit clearly pronounced softening and melting points, which are lower than the temperature of the onset of thermal degradation.
- Kudryavtsev,Meleshko,Kalbin,Bogorad,Lukasov,Baklagina
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p. 2171 - 2176
(2007/10/03)
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- Thermoplastic resin composition and a method of molding the same
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This invention provides a thermoplastic resin composition comprising a thermoplastic resin and 0.1 to 100 parts by weight, per 100 parts by weight of the thermoplastic resin, of an imide compound prepared, e.g., by dehydration condensation of 1,2,3,4-butanetetracarboxylic acid or a monoanhydride or a dianhydride thereof with a primary amine, and a method of molding the resin composition.
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- A Facile Reduction of Azides to Amines Using Hydrazine
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A variety of alkyl and aryl azides were reduced in high yields to the corresponding amines by reaction with hydrazine in refluxing methanol in the presence of palladium.
- Malik, A. A.,Preston, S. B.,Archibald, T. G.,Cohen, M. P.,Baum, K.
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p. 450 - 451
(2007/10/02)
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- Process for preparing of 3,3'-diamino diphenylsulfones
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3,3'-diamino diphenylsulfones are prepared by catalytically reducing and dehalogenating, in the presence of a reduction catalyst and a dehydrohalogenation agent, a diphenylsulfone compound of the general formula STR1 in which X is a halogen atom and Y is hydrogen or a halogen atom.
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