- A versatile strategy for the synthesis of 4,5-dihydroxy-2,3-pentanedione (DPD) and related compounds as potential modulators of bacterial quorum sensing
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Resistance to antibiotics is an increasingly serious threat to global public health and its management translates to significant health care costs. The validation of new Gram-negative antibacterial targets as sources for potential new antibiotics remains a challenge for all the scientists working in this field. The interference with bacterial Quorum Sensing (QS) mechanisms represents a potentially interesting approach to control bacterial growth and pursue the next generation of antimicrobials. In this context, our research is focused on the discovery of novel compounds structurally related to (S)-4,5-dihydroxy-2,3-pentanedione, commonly known as (S)-DPD, a small signaling molecule able to modulate bacterial QS in both Gram-negative and Gram-positive bacteria. In this study, a practical and versatile synthesis of racemic DPD is presented. Compared to previously reported syntheses, the proposed strategy is short and robust: it requires only one purification step and avoids the use of expensive or hazardous starting materials as well as the use of specific equipment. It is therefore well suited to the synthesis of derivatives for pharmaceutical research, as demonstrated by four series of novel DPD-related compounds described herein.
- Stotani, Silvia,Gatta, Viviana,Medda, Federico,Padmanaban, Mohan,Karawajczyk, Anna,Tammela, P?ivi,Giordanetto, Fabrizio,Tzalis, Dimitrios,Collina, Simona
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supporting information
(2018/10/20)
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- Direct Regioselective Synthesis of Tetrazolium Salts by Activation of Secondary Amides under Mild Conditions
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Tetrazolium salts are biologically active molecules that have found broad applications in biochemical assays. A regioselective synthesis of tetrazolium salts is described through a formal (3 + 2) cycloaddition. The possibility of employing simple amides and azides as starting material and the mild conditions allow a broad functional group tolerance.
- Tona, Veronica,Maryasin, Boris,De La Torre, Aurélien,Sprachmann, Josefine,González, Leticia,Maulide, Nuno
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supporting information
p. 2662 - 2665
(2017/05/24)
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- Chemo- and Stereoselective Transition-Metal-Free Amination of Amides with Azides
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The synthesis of α-amino carbonyl/carboxyl compounds is a contemporary challenge in organic synthesis. Herein, we present a stereoselective α-amination of amides employing simple azides that proceeds under mild conditions with release of nitrogen gas. The
- Tona, Veronica,De La Torre, Aurélien,Padmanaban, Mohan,Ruider, Stefan,González, Leticia,Maulide, Nuno
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supporting information
p. 8348 - 8351
(2016/07/26)
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- SPIROHYDANTOIN COMPOUNDS AND THEIR USE AS SELECTIVE ANDROGEN RECEPTOR MODULATORS
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The present invention relates to a compound of formula (1-1 ) in free form or in pharmaceutically acceptable salt form in which the substituents are as defined in the specification; to its preparation, to its use as a medicament and to medicaments comprising it. The present invention further provides a combination of pharmacologically active agents and a pharmaceutical composition.
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Page/Page column 69
(2013/09/12)
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- Poly(diiododiacetylene): Preparation, isolation, and full characterization of a very simple poly(diacetylene)
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Poly(diiodiacetylene), or PIDA, is a conjugated polymer containing the poly(diacetylene) (PDA) backbone but with only iodine atom substituents. The monomer diiodobutadiyne (1) can be aligned in the solid state with bis(nitrile) oxalamide hosts by hydrogen bonds between oxalamide groups and weak Lewis acid-base interactions (halogen bonds) between nitriles and iodoalkynes. The resulting cocrystals start out pale blue but turn shiny and copper-colored as the polymerization progresses. The development of a crystallization methodology that greatly improves the yield of PIDA to about 50% now allows the full characterization of the polymer by X-ray diffraction, solid-state 13C MAS NMR, Raman, and electron absorption spectroscopy. Comparison of a series of hosts reveals an odd-even effect in the topochemical polymerization, based on the alkyl chain length of the host. In the cocrystals formed with bis(pentanenitrile) oxalamide (4) and bis(heptanenitrile) oxalamide (6), the host/guest ratio is 1:2 and the monomer polymerizes spontaneously at room temperature, while in the case of bis(butanenitrile) oxalamide (3) and bis(hexanenitrile) oxalamide (5), where the host and guest form cocrystals in a 1:1 ratio, the polymerization is disfavored and does not go to completion. The topochemical polymerization can also be observed in water suspensions of micrometer-sized 6.1 cocrystals; the size distribution of these microcrystals, and the resulting polymer chains, can be controlled by sonication. Completely polymerized PIDA cocrystals show a highly resolved vibronic progression in their UV/vis absorption spectra. Extensive rinsing of the crystals in organic solvents such as methanol, THF, and chloroform separates the polymer from the soluble host. Once isolated, PIDA forms blue suspensions in a variety of solvents. The UV/vis absorption spectra of these suspensions match the cocrystal spectrum, without the vibronic resolution. However, they also include a new longer-wavelength absorption peak, associated with aggregation of the polymer chains.
- Luo, Liang,Wilhelm, Christopher,Sun, Aiwu,Grey, Clare P.,Lauher, Joseph W.,Goroff, Nancy S.
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p. 7702 - 7709
(2008/12/22)
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- Oxidation of azides by the HOF·CH3CN: A novel synthesis of nitro compounds
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The HOF·CH3CN complex, readily prepared by passing F 2 through aqueous acetonitrile, is an exceptionally efficient oxygen transfer agent. It is unique in its capacity to oxidize various azides into the corresponding nitro derivatives. This method requires short reactions times and room temperature or below, and the desired nitro compounds were usually isolated in very good yields. The respective nitroso derivatives are believed to be the intermediates in this reaction. Functional groups such as aromatic rings, ketones, nitriles, halides, alcohols, and esters are tolerated. Sulfides react with HOF·CH3CN usually at the same rate as azides. Amines and olefins, however, react faster, so they have to be protected first. Nitro derivatives with various oxygen isotopes can be made using the labeled H 18OF·CH3CN. In the case of chiral azides the stereochemistry around the nitrogen-bonded carbons is retained.
- Carmeli, Mira,Rozen, Shlomo
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p. 4585 - 4589
(2007/10/03)
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