- Pinning-down molecules in their self-assemblies with multiple weak hydrogen bonds of C[sbnd]H?F and C[sbnd]H?N
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Two-dimensional self-assemblies of four partially fluorinated molecules, 1,4-bis(2,6-difluoropyridin-4-yl)benzene, 4,4′-bis(2,6-difluoropyridin-4-yl)-1,1′-biphenyl, 4,4′-bis(2,6-difluoropyridin-4-yl)-1,1′:4′,1″-terphenyl and 4,4′-bis(2,6-difluoropyridin-3-yl)-1,1′-biphenyl, involving weak intermolecular C[sbnd]H?F and C[sbnd]H?N hydrogen bonds were systematically investigated on Au(111) with low-temperature scanning tunneling microscopy. The inter-molecular connecting modes and binding sites were closely related to the backbones of the building blocks, i.e., the molecule length determines its binding sites with neighboring molecules in the assemblies while the attaching positions of the N and F atoms dictate its approaching and docking angles. The experimental results demonstrate that multiple weak hydrogen bonds such as C[sbnd]H?F and C[sbnd]H?N can be efficiently applied to tune the molecular orientations and the self-assembly structures accordingly.
- Jin, Xin,Cramer, Jacob R.,Chen, Qi-Wei,Liang, Hai-Lin,Shang, Jian,Shao, Xiang,Chen, Wei,Xu, Guo-Qin,Gothelf, Kurt V.,Wu, Kai
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Read Online
- Synthesis of N-Alkylpyridin-4-ones and Thiazolo[3,2- a]pyridin-5-ones through Pummerer-Type Reactions
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N-Alkylated 4-pyridones were obtained through a one-pot procedure involving either normal or interrupted Pummerer reactions between triflic anhydride-activated sulfoxides and 4-fluoropyridine derivatives, followed by hydrolysis. On the other hand, triflic anhydride-activated benzyl 6-fluoro-2-pyridyl sulfoxide could react with alkenes or alkynes to afford thiazolo[3,2-a]pyridin-5-ones, via the pyridinium salt intermediates.
- Huang, Jingjia,Hu, Gang,An, Shaoyu,Chen, Dongding,Li, Minglei,Li, Pingfan
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p. 9758 - 9769
(2019/08/08)
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- Deprotometalation of substituted pyridines and regioselectivity-computed CH acidity relationships
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A series of methoxy- and fluoro-pyridines have been deprotometalated in tetrahydrofuran at room temperature by using a mixed lithium-zinc combination obtained from ZnCl2·TMEDA (TMEDA=N,N,N′,N′-tetramethylethylenediamine) and LiTMP (TMP=2,2,6,6-tetramethylpiperidino) in a 1:3 ratio, and the metalated species intercepted by iodine. Efficient functionalization at the 3 position was observed from 4-methoxy, 2-methoxy, 2,6-dimethoxy, 2-fluoro and 2,6-difluoropyridine, and at the 4 position from 3-methoxy and 2,3-dimethoxypyridine. Interestingly, clean dideprotonation was noted from 3-fluoropyridine (at C2 and C4) and 2,6-difluoropyridine (at C3 and C5). The obtained regioselectivities have been discussed in light of the CH acidities of the substrates, determined both in the gas phase (DFT B3LYP and G3MP2B3 levels) and in THF solution. In the case of methoxypyridines, the pKa values have also been calculated for complexes with LiCl and LiTMP.
- Hedidi, Madani,Bentabed-Ababsa, Ghenia,Derdour, A?cha,Halauko, Yury S.,Ivashkevich, Oleg A.,Matulis, Vadim E.,Chevallier, Floris,Roisnel, Thierry,Dorcet, Vincent,Mongin, Florence
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p. 2196 - 2205
(2016/04/09)
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- Facile preparation of 3-substituted-2,6-difluoropyridines: Application to the synthesis of 2,3,6-trisubstituted pyridines
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We report a facile method for the difluorination of 3-substituted-2,6-dichloropyridines using cesium fluoride as a fluorination reagent in dimethyl sulfoxide. It is proposed that this method for preparing 3-substituted-2,6-difluoropyridines is simpler and easier than those reported in previous literature. To examine the utility of 3-substituted-2,6-difluoropyridines in synthetic chemistry, we also demonstrate a subsequent conversion to 2,3,6-trisubstituted pyridines by a tandem nucleophilic aromatic substitution.
- Katoh, Taisuke,Tomata, Yoshihide,Tsukamoto, Tetsuya,Nakada, Yoshihisa
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supporting information
p. 6043 - 6046
(2015/10/28)
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- HETEROARYLOXYCARBOCYCLYL COMPOUNDS AS PDE10 INHIBITORS
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Heteroaryloxycarbocyclyl compounds of formula (I), and compositions containing them, and processes for preparing such compounds. Provided herein also are methods of treating disorders or diseases treatable by inhibition of PDE10, such as obesity, non-insulin dependent diabetes, schizophrenia, Huntington's Disease, bipolar disorder, obsessive -compulsive disorder, and the like. Formula (I)
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Page/Page column 68
(2011/12/02)
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- NOVEL COMPOSITIONS AND METHODS OF USE
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Described herein are novel enzyme inhibitors. In some embodiments the enzyme inhibitors are integrase inhibitors, particularly HIV integrase inhibitors. Also described herein are compositions containing them and methods of using them. Thus, the compounds and compositions described herein are useful for the in vitro and in vivo inhibition of HIV integrase as a method of treating or preventing HIV, AIDS or related disorders.
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Page/Page column 77
(2009/09/04)
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- Synthetic entries to substituted bicyclic pyridones
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(Chemical Equation Presented) The synthesis of 6,6- and 5,6-bicyclic pyridone scaffolds has been completed using (i) an intramolecular Mitsunobu reaction and/or (ii) hydrolysis of a bicyclic pyridinium salt intermediate. Regioselective functionalization o
- Cheng, Dachen,Croft, Laura,Abdi, Muna,Lightfoot, Andrew,Gallagher, Timothy
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p. 5175 - 5178
(2008/09/17)
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- The structural proliferation of 2,6-difluoropyridine through organometallic intermediates
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Contrary to a literature claim, 2,6-difluoropyridine-3-carboxaldehyde can be readily prepared by consecutive treatment of 2,6-difluoropyridine with lithium diisopropylamide and N,N-dimethylformamide. Regioselective displacements of fluorine from the aldehyde by nucleophiles were carried out. To demonstrate the versatility of the organometallic approach, some two dozens of further 2,6-difluoropyridine derivatives were prepared applying a combination of modern organometallic methods such as site selective hydrogen/metal and halogen/metal permutations and deprotonation-triggered heavy halogen migrations. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Schlosser, Manfred,Rausis, Thierry
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p. 1018 - 1024
(2007/10/03)
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- Deprotonation of fluoro aromatics using lithium magnesates
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Activated fluoro aromatics are deprotonated using lithium magnesates. 3-Fluoropyridine was deprotonated on treatment with 1/3 equiv of Bu 3MgLi in THF at -10°C. The lithium arylmagnesate formed was either trapped with electrophiles or involved
- Awad, Ha?an,Mongin, Florence,Trécourt, Fran?ois,Quéguiner, Guy,Marsais, Francis,Blanco, Fernando,Abarca, Belén,Ballesteros, Rafael
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p. 6697 - 6701
(2007/10/03)
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- Pyridine derivatives in liquid crystalline medium useful for electrooptical display elements
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The invention relates to pyridine derivatives of the formula I STR1 wherein R1, A, Z, r, X, s and R2 have the meaning given in claim 1, and their use as components for liquid crystal media for electrooptical display elements based on the ECB effect.
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