- Generation and reactions of pyridyllithiums via Br/li exchange reactions using continuous flow microreactor systems
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A continuous flow microreactor method for generating and carrying out reactions on pyridyllithiums has been developed based on Br/Li exchange reactions of bromopyridines and dibromopyridines. The reactions can be carried out without using cryogenic conditions by virtue of short residence times and efficient heat transfer, while very low temperatures such as-78 or-110°C are required for conventional batch macro methods. Moreover, sequential introduction of two different electrophiles has been successfully achieved using dibromopyridines in an integrated flow microreactor system composed of four micromixers and four microtube reactors.
- Nagaki, Aiichiro,Yamada, Daisuke,Yamada, Shigeyuki,Doi, Masatomo,Ichinari, Daisuke,Tomida, Yutaka,Takabayashi, Naofumi,Yoshida, Jun-Ichi
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p. 199 - 207
(2013/03/28)
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- Promiscuous G-protein compositions and their use
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Disclosed are compositions and methods for their use, such as in identifying G-protein coupled receptors and ligands and compounds that modulate signal transduction. The compositions and methods employ promicuous G-proteins. Activation of the promiscous G-protein can be detected in a variety of assays, including assays in which activation is indicated by a change in fluorescence emission of a sample that contains the composition.
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- Nucleophilic addition to 3-substituted pyridinium salts: Expedient syntheses of (-)-L-733,061 and (-)-CP-99,994
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(Chemical Equation Presented) The addition of nucleophiles to 3-substituted pyridinium salts prepared from N-methylbenzamide and various pyridines has been investigated. Good to excellent regioselectivities favoring the 2,3-disubstituted 1,2-dihydropyridines were observed. The resulting 1,2-dihydropyridines led to the corresponding 2,3-disubstituted pyridines upon treatment with Mn(OAc)3/NaIO4. This methodology was also successfully applied to the enantioselective syntheses of (-)-L-733,061 and (-)-CP-99,994, two members of a new class of highly potent, nonpeptide, Substance P antagonists.
- Lemire, Alexandre,Grenon, Michel,Pourashraf, Mehrnaz,Charette, Andre B.
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p. 3517 - 3520
(2007/10/03)
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- Inhibitors of cell proliferation, angiogenesis, fertility, and muscle contraction
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The invention concerns inhibitors of cell proliferation, angiogenesis, fertility, and muscle contraction, characterized by formula I wherein, X, Y and Z independently represent C or N; ------ is an optional double bond; n is 0 or 1; R1, R2, and R4 independently represent hydrogen, a chemical bond, C1-10 alkyl; C2-10 alkenyl; C2-10 alkinyl; aryl; aryl-C1-10 alkyl; C3-10 heterocyclyl; C5-10 heteroaryl; halo, CF3; NO2; NHC(O)R*, OR, said alkyl, alkenyl, alkinyl, aryl, arylalkyl, heterocyclyl, or heteroaryl being optionally substituted; R3, R5, and R6 independently represent hydrogen, C1-10alkyl; C2-10 alkenyl; C2-10 alkinyl; aryl; aryl-C1-10alkyl; C3-10 heterocyclyl; C5-10 heteroaryl; halo, CF3; NO2; NHC(O)R*, OR, said alkyl, alkenyl, alkinyl, aryl, heterocyclyl, or heteroaryl being optionally substituted; or R5 and R6 together form a 5- or 6-member aryl, heterocyclyl or heteroaryl group; R is hydrogen or C1-6 alkyl; R* is hydrogen, or C1-6 alkyl, or OH, wherein the optional substituents are preferably selected from the group of one to three OH, C1-6 alkyl, halo, NO2, C1-6 alkoxy, and CF3, or a pharmaceutically acceptable salt thereof.
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- Synthesis of 2,3-disubstituted pyrroles and pyridines from 3-halo-1-azaallylic anions
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A new synthesis of 2,3-disubstituted pyrroles and pyridines is described. The reaction of 3-halo-1-azaallylic carbanions, regiospecifically generated from α-halogenated ketimines, with ω-iodoazides led to the regiospecific formation of ω-azido-α-haloketimines. Treatment of these functionalized imines with tin(II) chloride afforded halogenated five- and six-membered cyclic imines, which were transformed under mild conditions into 2,3-disubstituted pyrroles and pyridines. The stereoselective reduction of 2,3-dialkyl-3-chloro-1-pyrrolines to afford cis-2,3-dialkyl-3-chloropyrrolidines is also reported.
- Aelterman,De Kimpe,Tyvorskii,Kulinkovich
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- Titanocene(III) catalyzed homogeneous hydrosilation-hydrogenation of pyridines
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The homogeneous catalytic hydrosilation-hydrogenation of pyridines is observed in the presence of Cp2TiMe2 (Cp = η5-C5H5) and CpCp*TiMe2 (Cp* = η5-C5Me5) as catalysts and using PhSiH3 or PhMeSiH2 as the source of Si-H. Under appropriate conditions, and with appropriate ring-substitution, good yields of the N-silyldihydropyridine or N-silyltetrahydropyridine products are be obtained. Although complete saturation is not achieved with organosilane alone, carrying out the reaction under moderate H2 pressures can give excellent yields of N-silylpiperidines. Under moderate pressures of H2, [Cp2TiH]2 catalyzes rapid H-D exchange between H2 and the 2- and 6-positions of C5D5N. Under the same conditions, only traces of hydrogenation are observed. This, together with the regioselectivity of 3-picoline hydrosilation-hydrogenation, leads to the conclusion that the key step in the reaction is probably addition of Ti-Si to C=N.
- Harrod,Shu,Woo,Samuel
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p. 1075 - 1085
(2007/10/03)
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- Complexing agents and targeting radioactive immunoreagents useful in therapeutic and diagnostic imaging compositions and methods
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A targeting radioactive immunoreagent comprising a compound having the structure STR1
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- Process for the preparation of substituted cyclopropanecarbaldehydes
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The invention relates to a process for the preparation of cyclopropanecarbaldehydes of formula STR1 in which R1 is C1 -C4 alkyl or benzyl, which comprises (a) reacting a tetrahydrofuran of formula STR2 in which X is halogen and R2 is unsubstituted or halo-substituted C1 -C10 alkyl, C3 -C6 -cycloalkyl that is unsubstituted or substituted by halogen, C1 -C4 alkyl or by C1 -C4 alkoxy, or phenyl or benzyl each of which is unsubstituted or substituted by halogen, C1 -C4 alkyl, C1 -C4 alkoxy, nitro or cyano, with a halogenating agent to form a 1,2,4-trihalobutyl ether of formula STR3 in which X is halogen and R2 is unsubstituted or halo-substituted C1 -C10 alkyl, C3 -C6 cycloalkyl that is unsubstituted or substituted by halogen C1 -C4 alkyl or by C1 -C4 alkoxy, or phenyl or benzyl each of which is unsubstituted or substituted by halogen, C1 -C4 alkyl, C1 -C4 alkoxy, nitro or cyano, and (b) then reacting the compound of formula III with an aqueous bisulfite solution to form a bisulfite adduct of formula STR4 in which X is a halogen and Y is a cation equivalent of an alkali metal or alkaline earth metal ion, and (c) then cyclising the adduct, in the presence of a base, with a thiolate of formula in which R1 is C1 -C4 alkyl or benzyl and Z is a cation equivalent of an alkali metal or alkaline earth metal ion, to form a cyclopropanecarbaldehyde of formula I, and to the individual Process Steps (a), (b) and (c) and the combinations thereof (a)+(b) and (b)+(c), and to the novel intermediates of formulae III and IV.
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- An Improved Liquid-Phase Synthesis of Simle Alkylpyridines
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The synthesis of pyridines from mixtures of aldehydes or ketones and NH3 in the liquid phase has been reinvestigated, using continuous dosage of the carbonyl components to the reaction mixture.The main product from the reaction of acetaldehyde and formaldehyde is 3-methylpyridine (6), which is also the main product from the reaction of acrolein or a mixture of crotonaldehyde and formaldehyde under the same conditions.The reaction of other aldehydes with formaldehyde give 3,5-dialkylpyridines, e.g. 10, 16.Acetone reacts with either formaldehyde or acetaldehyde to give polysubstituted alkylpyridines.A mechanistic pathway is proposed which accounts for the formation of the observed products.
- Grayson, J. Ian,Dinkel, Rolf
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p. 2100 - 2110
(2007/10/02)
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- Transformations of pyridine bases on a nickel-aluminum catalyst
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The electronic structures of some pyridine bases are analyzed by means of 1H and 13C NMR spectroscopic data for substituted pyridines and the calculated bond orders in the pyridine ring. The differences in the chemical bonds in the pyridine ring of isomeric methylpyridines and the carbon-carbon bonds between the ring and the methyl groups in these compounds are in agreement with the experimental data on the thermal stability of the simplest pyridine bases and the gas-phase transformation of the isomeric methylpyridines on an industrial nickel-aluminum catalyst. The possibility of obtaining mono- or dialkylpyridines under these conditions, depending on the structure of the starting pyridine bases, is demonstrated.
- Antonova,Ovchinnikova,Bespalov,Serova,Promonenkov,Ustavshchikov
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p. 280 - 283
(2007/10/02)
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