- Selective C-H Iodination of (Hetero)arenes
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Iodoarenes are versatile intermediates and common synthetic targets in organic synthesis. Here, we present a strategy for selective C-H iodination of (hetero)arenes with a broad functional group tolerance. We demonstrate the utility and differentiation to other iodination methods of supposed sulfonyl hypoiodites for a set of carboarenes and heteroarenes.
- Tanwar, Lalita,B?rgel, Jonas,Lehmann, Johannes,Ritter, Tobias
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supporting information
p. 5024 - 5027
(2021/06/30)
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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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- Synthesis of N-pyridyl azoles using a deprotometalation-iodolysis-N-arylation sequence and evaluation of their antiproliferative activity in melanoma cells
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N-Arylation of pyrrole with 3-iodo-4-methoxypyridine was investigated by copper catalysis under different conditions. The best conditions, that proved to be protocol A (CuI, DMEDA or TMEDA, K3PO4, DMF at 110?°C) and above all protocol B (Cu2O, Cs2CO3, DMSO at 110?°C), were applied to the synthesis of various N-(methoxypyridyl) pyrroles, indoles and benzimidazoles. The behavior of the different iodinated methoxypyridines was rationalized by evaluating the partial positive charge on the carbon bearing iodine from the1H NMR chemical shift of the corresponding deiodinated substrates. The reaction was next connected with the deprotometalation-iodolysis step generating iodinated methoxypyridines: straight involvement of the crude iodo intermediates in pyrrole N-arylation afforded the expected N-(methoxypyridyl) pyrroles in good yields. Several synthesized N-(methoxypyridyl) azoles exerted low to moderate antiproliferative activity in A2058 melanoma cells.
- Hedidi, Madani,Erb, William,Bentabed-Ababsa, Ghenia,Chevallier, Floris,Picot, Laurent,Thiéry, Valérie,Bach, Stéphane,Ruchaud, Sandrine,Roisnel, Thierry,Dorcet, Vincent,Mongin, Florence
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p. 6467 - 6476
(2016/09/23)
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- Noncryogenic synthesis of functionalized 2-methoxypyridines by halogen-magnesium exchange using lithium dibutyl(isopropyl)magnesate(1-) and lithium chloride
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2-Methoxypyridines functionalized in the 3-, 5-, or 6-position and 2,6-dimethoxypyridines functionalized in the 3-position were prepared from the corresponding bromo or iodo analogues by using lithium dibutyl(isopropyl) magnesate(1-) and lithium chloride
- Struk, Lukasz,Sosnicki, Jacek G.
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experimental part
p. 735 - 746
(2012/04/04)
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- Deprotonative metalation of substituted aromatics using mixed lithium-cobalt combinations
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The deprotonation of anisole was attempted using different homo- and heteroleptic TMP/Bu mixed lithium-cobalt combinations. Using iodine to intercept the metalated anisole, an optimization of the reaction conditions showed that in THF at room temperature 2 equiv of base were required to suppress the formation of the corresponding 2,2′-dimer. The origin of the dimer was not identified, but its formation was favored with allyl bromide as electrophile. The metalated anisole was efficiently trapped using iodine, anisaldehyde, and chlorodiphenylphosphine, and moderately employing benzophenone, and benzoyl chloride. 1,2-, 1,3-, and 1,4-dimethoxybenzene were similarly converted regioselectively to the corresponding iodides. It was observed that 2-methoxy- and 2,6-dimethoxypyridine were more prone to dimerization than the corresponding benzenes when treated similarly. Involving ethyl benzoate in the metalation-iodination sequence showed that the method was not suitable to functionalize substrates bearing reactive functions.
- Dayaker, Gandrath,Chevallier, Floris,Gros, Philippe C.,Mongin, Florence
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experimental part
p. 8904 - 8910
(2011/01/04)
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- CHEMICAL COMPOUNDS AND PROCESSES
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The present invention relates generally to chemical compounds and methods for their use and preparation. In particular, the invention relates to chemical compounds which may possess useful therapeutic activity, use of these compounds in methods of therapy and the manufacture of medicaments as well as compositions containing these compounds.
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Page/Page column 68-69
(2008/12/06)
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