- Enhancing the Extent of Enolization for α-C-H Bonds of Aliphatic Carboxylic Acid Equivalents via Ion Pair Catalysis: Application toward α-Chalcogenation
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In general, the α-functionalization of carboxylic acid derivatives requires either a transition metal catalyst or a stoichiometric activating agent/strong base/external additive. A transition metal free α-chalcogenation of aliphatic carboxylic acid equivalents is reported herein via ion pair formation using K3PO4 as a catalyst. Mild conditions, broad scope, scalability of the process, attaining bioactive glucokinase activators, and some synthetic intermediates establish merits of the strategy.
- Kumar, Jogendra,Singh, Anupam Kumar,Gupta, Aniket,Bhadra, Sukalyan
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p. 6330 - 6335
(2022/04/28)
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- Catalytic Enantioselective Access to Dihydroquinoxalinones via Formal α-Halo Acyl Halide Synthon in One Pot
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An enantioselective one-pot catalytic strategy to dihydroquinoxalinones, featuring novel 1-phenylsulfonyl-1-cyano enantioenriched epoxides as masked α-halo acyl halide synthons, followed by a domino ring-opening cyclization (DROC), is documented. A popula
- Crescenzi, Carlo,Lattanzi, Alessandra,Mancinelli, Michele,Mazzanti, Andrea,Meninno, Sara,Volpe, Chiara
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p. 23819 - 23826
(2021/10/04)
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- DABCO mediated one pot synthesis of sulfoxonium ylides under blue LED
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DABCO mediated practical and convenient one pot method has been developed to access sulfoxonium ylides under photoredox and metal free conditions at room temperature. The protocol explored the reactivity of DMSO and α-aryl-α-diazo esters in presence of DABCO under blue LED condition. We demonstrated the generality of this protocol by synthesizing a variety of sulfoxonium ylides in very good yields. The practicality of the protocol has been demonstrated by the gram scale synthesis as well as by the extension of this protocol to synthesize precursors of biologically active compounds. This straightforward and practical method offers an alternative route to access very useful sulfoxonium ylides from α-aryl-α-diazoacetates.
- Khade, Vikas V.,Thube, Archana S.,Warghude, Prakash K.,Bhat, Ramakrishna G.
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- Expeditious synthesis of C2- or N4-aryl-1,4-benzothiazin-3-one via orthogonal Pd-catalyzed C-arylation and Cu-catalyzed N-arylation
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Direct, chemo-specific arylation at C-2 or N-4 of 1,4-benzothiazin-3-one with aryl halides, based on Pd or Cu catalyst system, respectively, provided easy entry to arylated derivatives, a class of molecules not easily accessible via existing methods. Under Pd-catalysis conditions with LiHMDS as the base, N-arylation of 1,4-benzothiazin-3-one was inhibited leading to Cα-arylation of a secondary amide without the need for protection and de-protection of more acidic amido NH.
- Huang, Wei-Sheng,Xu, Rongsong,Dodd, Rory,Shakespeare, William C.
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p. 441 - 444
(2014/01/06)
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- LXR modulators
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A compound of formula I wherein A, X, q, R1, R2a, R2b, R2c, R3a, and R3b are defined herein.
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Page/Page column 102-103
(2010/11/26)
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- Regioselective one pot synthesis of 2-alkyl/aryl-4H-benzo[1,4]thiazine-3- one via microwave irradiation
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A series of 2-alkyl/aryl-4H-benzo[1,4]thiazine-3-ones have been synthesized by microwave irradiation of ethyl-2-bromo-2-alkyl/aryl acetate and 2-amino thiophenol in the presence of 1,8-diazabicyclo-[5.4.0]undec-7-ene and N-methylpiperidine. All compounds were characterized by 1H NMR, 13C NMR and elemental analyses, and by X-ray crystallography in the case of 2-methyl-4H-benzo[1,4]thiazin-3-one.
- Kamila, Sukanta,Koh, Benjamin,Khan, Omair,Zhang, Hongming,Biehl, Edward R.
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p. 1641 - 1646
(2007/10/03)
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- Synthesis of 2H-1,4-benzothiazin-3(4H)-ones and 2H-1,4-benzoselenazin-3(4H)-ones with the aid of samarium(II) iodide
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Bis(o-nitrophenyl) disulfides or diselenides were easy to reduce by samarium(II) iodide to produce the active intermediates 2 in situ, which readily react with α-halocarboxylic derivatives to yield the corresponding products 2H-1,4-benzothiazin-3(4H)-ones and 2H-1,4-benzoselenazin-3(4H)-ones, respectively, in moderate to high yields under mild conditions.
- Zhong, Weihui,Zhang, Yongmin
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p. 3125 - 3127
(2007/10/03)
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- A Convenient and General Synthesis of 2-Aryl- and 2-Pyridyl-3-oxo-3,4-dihydro-2H-1,4-benzothiazines
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The reaction of bis(2-aminophenyl) disulphide 1 with methyl or ethyl aryl- or pyridylacetates and sodium hydride gives the title compounds in good yield and high purity.The reaction is general, the starting materials easily available and the workup is simple and rapid.
- Jacobsen, Niels,Kolind-Andersen, Hans
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p. 911 - 914
(2007/10/02)
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- Heterocyclic aldose reductase inhibitors and methods of using them
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The invention relates to new compounds of the formula: STR1 Aldose reductase inhibitors. Treatment of certain complications of diabetes.
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- SYNTHESIS AND REACTIONS OF 3-PHENYL-3,4-DIHYDRO-1,4-QUINOXALIN-2(1H)-ONE AND ITS HETEROCYCLIC ANALOGUES
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The lactams quinoxalinone 3a, benzothiazinone 3b and benzothiazinone 3c were synthesized by reactions of methyl 2-bromo-2-phenylethanoate 1 with orthosubstituted arylamines 2a-2c.Subsequent reductive alkylation of the lactams with sodium hydride and iodom
- Olagbemiro, T.O.,Nyakutse, C.A.,Lajide, L.,Agho, M.O.,Chukwu, C.E.
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p. 473 - 480
(2007/10/02)
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- SINTESI ED ATTIVITA ANTIINFIAMMATORIA DI ALCUNI DERIVATI 1,4-BENZOTIAZINICI
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A new series of dihydro-4H-1,4-benzothiazine derivatives was prepared.These compounds were obtained by reductive N-alkylation reaction with sodium borohydride in acetic acid of the corresponding 4H-1,4-benzothiazine.Some of the latter compounds were synthesized by a new synthetic method employing 2-aminobenzenethiol and alkynes as starting material. - Preliminary pharmacological data on the antiinflammatory activity of these compounds by using carrageenin paw edema assay are reported.
- Trapani, G.,Reho, A.,Morlacchi, F.,Latrofa, A.,Marchini, P.,et al.
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p. 369 - 376
(2007/10/02)
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- REACTIONS OF 4-ACETOXY-2H-1,4-BENZTHIAZIN-3(4H)-ONE
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4-Acetoxy-2H-1,4-benzthiazin-3(4H)-one (5), a unique arylhydroxamic acid derivative, reacted with nucleophiles.The position 2 of compound 5 is the center of high reactivity, and even benzene reacted with 5 nucleophilically at the position.
- Kugai, Norio,Hashimoto, Yuichi,Shudo, Koichi
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p. 277 - 280
(2007/10/02)
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- Non-stereospecific Ring Expansion Reactions of Benzothiazoline Sulfoxides
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The stereochemistry of novel ring expansion of benzothiazoline sulfoxides to benzothiazines by reaction with acetic anhydride was examined.Reaction of trans-3-acetyl-2-ethyl-2-methylbenzothiazoline 1-oxide with acetic anhydride afforded 4-acetyl-3-ethylid
- Shimizu, Hiroshi,Ueda, Norihiro,Kataoka, Tadashi,Hori, Mikio
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p. 2571 - 2590
(2007/10/02)
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