- t-BuOK-promoted methylthiolation of aryl fluorides with dimethyldisulfide under transition-metal-free and mild conditions
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In the presence of potassium tert-butoxide (t-BuOK), the cross-coupling reaction between aryl fluorides and dimethyldisulfide was developed. A series of aryl methyl sulfides were obtained in moderate to good yields under transition-metal-free and mild conditions.
- Huang, Dayun,Wu, Xiangmei
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- Copper-Catalyzed Methylthiolation of Aryl Iodides and Bromides with Dimethyl Disulfide in Water
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An efficient route to aryl methyl sulfides through the copper-catalyzed coupling reaction of aryl iodides or bromides with dimethyl disulfide in water is described. Electron-donating and electron-withdrawing functional groups in the substrates were tolerated, and the corresponding products were obtained in moderate to good yields.
- Wang, Ying-Yu,Wu, Xiang-Mei,Yang, Ming-Hua
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supporting information
(2020/07/20)
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- Metal-free S-methylation of diaryl disulfides with di-tert-butyl peroxide
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An efficient approach for S-methylation of diaryl disulfides with di-tert-butyl peroxide under metal-free and neutral conditions was established. The present protocol shows good functional group tolerance to afford aryl methyl sulfides in moderate to good
- Wu, Xiangmei,Wang, Yan
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supporting information
p. 1240 - 1243
(2018/03/08)
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- Metal-Free, DTBP-Mediated Methylthiolation of Arylboronic Acids with Dimethyldisulfide
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An efficient method for the C-S bond formation via the coupling reaction of arylboronic acids with dimethyldisulfide has been developed under the metal-free conditions. This novel protocol provides an attractive route for the synthesis of aryl methyl sulf
- Wu, Xiang-Mei,Lou, Jia-Ming,Yan, Guo-Bing
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supporting information
p. 2269 - 2273
(2016/10/30)
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- The synthesis of OSU 6162: Efficient, large-scale implementation of a Suzuki coupling
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The synthesis of the chiral, nonracemic 3-aryl piperidine, OSU 6162 (1), a potential CNS agent from Pharmacia Corporation, is presented. The key construction in the described synthesis is a palladium-catalyzed aryl cross-coupling reaction between bromosulfone (4) and pyridyl borane (14). Initially developed conditions for this Suzuki reaction, conducted in tetrahydrofuran/aqneous hydroxide, delivered free base (6) or hydrochloride salt (15a) in reproducible 80% yield. However, by changing the solvent to toluene and the base to carbonate, significant decreases in catalyst requirement were realized, and the methane sulfonate salt (15b) of the coupled product could be obtained in reproducible 92-94% yield on 200-kg input. The success of the Suzuki reaction was critically dependent on a bulk source of the pyridyl borane coupling partner. Cryogenic conditions were developed for its generation via lithium-halogen exchange to generate thermally labile 3-lithiopyridine followed by transmetalation with diethylmethoxy borane. This highly exothermic series of transformations yielded crystalline diethyl-3-pyridyl borane in reproducible 75-80% yield on scales ranging up to 200-kg input. Selective reduction of the biaryl, classical resolution and introduction of the propyl group via the Gribble reductive amination procedure completed the synthesis of OSU 6162 free base. This route was employed to deliver over 35 kg of clinical-quality bulk drug in short order.
- Lipton, Michael F.,Mauragis, Michael A.,Maloney, Mark T.,Veley, Michael F.,VanderBor, Dale W.,Newby, John J.,Appell, Robert B.,Daugs, Edward D.
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p. 385 - 392
(2013/09/06)
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- Efficient photoacids based upon triarylamine dialkylsulfonium salts
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New triarylamine dialkylsulfonium salts that are photosensitive in the near-ultraviolet have been prepared. The quantum yields of photoacid generation were found to be ~0.5 and are independent of the counterion. On the other hand, the efficiencies of the sulfonium salts toward the photopolymerization of cyclohexene oxide depend on the counterion and the sulfonium substituents. Photopolymerization kinetic studies demonstrate that these triphenylamine sulfonium salts are highly efficient cationic photoinitiators.
- Zhou, Wenhui,Kuebler, Stephen M.,Carrig, Dave,Perry, Joseph W.,Marder, Seth R.
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p. 1897 - 1901
(2007/10/03)
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- 2-Halo-2-cyclohexenols from 6,6-dihalobicyclo-[3.1.0]hexanes and dimethyl sulfoxide. Studies towards a non-basic hydroxide equivalent
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A practical, high yielding, cheap and mild method for the synthesis of 2-halo-2-cycloalkenols, especially 2-bromo-2-cyclohexenol, is reported. Direct conversion from a variety of thermally labile n,n-dihalobicyclo[n-3.1.0]alkanes to 2-halo-2-cycloalkenols can be achieved without using silver salts by simple heating in DMSO. The intermediate 1,n-dihalocycloalkenes immediately undergo indirect allylic substitution with DMSO to yield the corresponding halocycloalkenols. A possible mechanism for the substitution step comprises nucleophilic attack by DMSO followed by a Pummerer rearrangement and hydrolytic decomposition. Kinetic and mechanistic experiments to verify the course of the reaction are presented. Acta Chemica Scandinavica 1997.
- Wessjohann, Ludger A.,Muehlbauer, Andrea,Sinks, Udo
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p. 1112 - 1115
(2007/10/03)
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- Syntheses of various 5-(3′-substituted phenyl)uracils
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The Suzuki Pd(0)-catalysed coupling between arylboronic acids and aryl bromides or iodides in weakly alkaline medium has been used for the preparation of 5-(3′-chlorophenyl)-, 5-(3′-iodophenyl)-, 5-(3′-aminophenyl)-, 5-(3′-azidophenyl)-, 5-(3′-methylthiophenyl)- and 5-(3′-styryl)-substituted 2,4-di-t-butoxypyrimidines. In the coupling between 2,4 di-t-butoxy-5-pyrimidineboronic acid and the six different aryl halides that were used as coupling partners, only 1-azido-3-bromobenzene did not give satisfactory yields, 18%. The other five aryl halides gave the desired 5-(3′-substituted phenyl)-2,4-di-t-butoxypyrimidines in 41-92% yield. Dealkylation of these five 5-(3′-substituted phenyl)-2,4-di-t-butoxypyrimidines in 2.5M hydrochloric acid gave the corresponding 5-(bromoaryl)uracils in almost quantitative yields. 5-(3′-Azidophenyl)uracil was prepared in 43% yield directly from 5-(3′-aminophenyl)-2,4-di-t-butoxypyrimidine.
- Wellmar, Ulf,Hoernfeldt, Anna-Britta,Gronowitz, Salo
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p. 409 - 414
(2007/10/03)
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- An Efficient Synthesis of the Novel Dopamine Autoreceptor Antagonist S-(-)-OSU6162, via Palladium Catalyzed Cross-Coupling Reaction.
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Optically active S-(-)-OSU6162 ((-)-1) has been synthesized in 4 steps with an overall yield of 48 percent.The four steps consists of palladium catalyzed cross-coupling, catalytic hydrogenation, classical resolution with tartaric acid and reductive amination.
- Sonesson, Clas,Lindborg, Jonas
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p. 9063 - 9066
(2007/10/02)
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- Development of a novel series of styrylquinoline compounds as high- affinity leukotriene D4 receptor antagonists: Synthetic and structure- activity studies leading to the discovery of (±)-3-[[[3-[2-(7-chloro-2- quinolinyl)-(E)-ethenyl]phenyl][[3-(dimethylamino)-3- oxopropyl]thio]methyl]thio]propionic acid
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Based on LTD4 receptor antagonist activity of 3-(2-quinolinyl-(E)- ethenyl)pyridine (2) found in broad screening, structure-activity studies were carried out which led to the identification of 3-[[[3-[2-(7-chloro-2- quinolinyl)-(E)-ethenyl]phenyl][[3-(dimethylamino)-3- oxopropyl]thio]methyl]thio]propionic acid (1, MK-571) as a potent and orally active LTD4 receptor antagonist. These studies demonstrated that a phenyl ring could replace the pyridine in 2 without loss of activity, that 7-halogen substitution in the quinoline group was optimal for binding, that the (E)- ethenyl linkage was optimal, that binding was enhanced by incorporation of a polar acidic group or groups in the 3-position of the aryl ring, and that two acidic groups could be incorporated via a dithioacetal formed from thiopropionic acid and the corresponding styrylquinoline 3-aldehyde to yield compounds such as 20 (IC50 = 3 nM vs [3H]LTD4 binding to the guinea pig lung membrane). It was found that one of the acidic groups could be transformed into a variety of the amides without loss of potency and that the dimethylamide 1 embodied the optimal properties of intrinsic potency (IC50 = 0.8 nM on guinea pig lung LTD4 receptor) and oral in vivo potency in the guinea pig, hyperreactive rat, and squirrel monkey. The evolution of 2 to 1 involves the increase of >6000-fold in competition for [3H]LTD4 binding to guinea pig lung membrane and a >40-fold increase in oral activity as measured by inhibition of antigen-induced dyspnea in hyperreactive rats.
- Zamboni,Belley,Champion,Charette,DeHaven,Frenette,Gauthier,Jones,Leger,Masson,McFarlane,Metters,Pong,Piechuta,Rokach,Therien,Williams,Young
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p. 3832 - 3844
(2007/10/02)
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- 2-substituted quinoline dioic acids and pharmaceutical compositions
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Compounds having the formula: STR1 are antagonists of leukotrienes and inhibitors of their biosynthesis. These compounds are useful as anti-asthmatic, anti-allergic, anti-inflammatory, and cytoprotective agents.
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- 2-Substituted quinoline dioic acids
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Compounds having the formula: are antagonists of leukotrienes and inhibitors of their biosynthesis. These compounds are useful as anti-asthmatic, anti-allergic, anti-inflammatory, and cytoprotective agents.
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