- Fluorescence microscopy visualization of contacts between objects
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The area of contact between two objects was detected by using the strong enhancement of the fluorescence of rigidochromic probe molecules attached to one of the surfaces. Confinement of the molecules suppresses nonradiative decay and turns on the fluorescence. The approach is demonstrated by imaging of the contact area of a plastic sphere in contact with a flat glass surface. Our results agree excellently with the prediction of Hertz's classical theory based on elastic deformation. All the fun of the surface: By using rigidochromic fluorescent probe molecules attached to a surface, the contact area between the surface and an object can be visualized. Confinement of the molecules suppresses nonradiative decay and turns on the fluorescence.
- Suhina, Tomislav,Weber, Bart,Carpentier, Chantal E.,Lorincz, Kinga,Schall, Peter,Bonn, Daniel,Brouwer, Albert M.
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Read Online
- Halogen-bonded iodonium ion catalysis: A route to α-hydroxy ketones: Via domino oxidations of secondary alcohols and aliphatic C-H bonds with high selectivity and control
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A domino synthesis of α-hydroxy ketones has been developed from benzylic secondary alcohols employing catalytic iodonium ions stabilized by DMSO. The reaction proceeds through an unprecedented sequential oxidation of alcohols to ketone and its α-hydroxylation in a controlled manner. The spectroscopic evidence establishes the possibility of formation of a stable halogen-bonded adduct between DMSO and iodonium ions.
- Guha, Somraj,Kazi, Imran,Mukherjee, Pranamita,Sekar, Govindasamy
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supporting information
p. 10942 - 10945
(2017/10/13)
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- Α - hydroxy ketone compound low priced high-efficient synthetic method
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The invention discloses a cheap and efficient synthesis method of an alpha-hydroxyketone compound. The synthesis method is characterized in that a carbonyl compound undergoes an oxidation hydroxylation reaction at 10-120DEG C under normal pressure with iodine simple substance, N-bromosuccimide, copper bromide, bromine simple substance, hydrogen bromide, N-iodosuccimide or hydrogen iodide as a catalyst, sulfoxide as an oxidant, water or sulfoxide as a hydroxy source and sulfoxide, ethyl acetate, N,N-dimethyl formamide, acetonitrile, toluene, 1,4-dioxane, 1,2-dichloroethane, tetrahydrofuran or H2O as a solvent, and converts into the alpha-hydroxyketone compound in a high selectivity manner. Compared with traditional synthesis methods, the method disclosed in the invention has the advantages of simple operation, high yield, simple conditions, easy purification, small waste discharge amount, simple reaction apparatus, and easy industrial production. The method has wide applicability and can be used for synthesizing various alpha-hydroxyketone compounds.
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Paragraph 0178-0181
(2017/08/25)
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- I2- or NBS-catalyzed highly efficient α-hydroxylation of ketones with dimethyl sulfoxide
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An efficient method for the direct preparation of high synthetic valuable α-hydroxycarbonyls is described. The simple and readily available I2 or NBS was used as catalyst. DMSO acts as the oxidant, oxygen source, and solvent. A diverse range of tertiary Csp3-H bonds as well as more challenging secondary Csp3-H bonds could be hydroxylated in this transformation. The reaction is mild, less toxic and easy to perform.
- Liang, Yu-Feng,Wu, Kai,Song, Song,Li, Xinyao,Huang, Xiaoqiang,Jiao, Ning
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supporting information
p. 876 - 879
(2015/04/14)
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- Fluorophore compounds and their use in biological systems
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Fluorophore compounds and methods for their use are disclosed. The fluorophores contain a 2-dicyanomethylen-3-cyano-2,5-dihydrofuran (DCDHF) moiety and one or more donor groups conjugated to the 2-dicyanomethylen-3-cyano-2,5-dihydrofuran group. The donor
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- PREPARATION OF ALPHA-HYDROXYKETONES
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A process for the preparation of an 1, 1 -disubstituted oxirane is disclosed, wherein an organic sulphide is reacted in a polar solvent with an educt containing a leaving group attached to a primary or secondary carbon atom, and/or the sulfonium salt formed in this way is reacted with a ketone in presence of a base and a polar solvent. Oxiranes of the type obtained may be further converted into the corresponding α-hydroxyketone or α-aminoketone, either in one step by subjecting to aerobic oxidation in the presence of a transition metal catalyst, or in two steps by hydrolyzation in the presence of an aqueous acid to the corresponding dialcohol and subsequent selective oxidation. Further described are some novel epoxide intermediates. The α-hydroxyketones and α-aminoketones thus obtainable are useful inter alga as photoinitiators.
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