- Further Insight into the Castagnoli-Cushman-type Synthesis of 1,4,6-Trisubstituted 1,6-Dihydropyridin-2-(3 H)-ones from 3-Arylglutaconic Acid Anhydrides
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The earlier reported three-component Castagnoli-Cushman-type synthesis of 1,4,6-trisubstituted 1,6-dihydropyridin-2-(3H)-ones from 3-arylglutaconic acids, primary amines, and aromatic aldehydes has been further investigated. It was shown to proceed via 3-arylglutaconic anhydrides, which, in turn, were found to give superior results in the two-component reactions with imines. The initial formation of the Castagnoli-Cushman carboxylic acids was shown to be the case, and their decarboxylation was found to follow a complex, forked pathway, which was confirmed by deuterium incorporation experiments.
- Firsov, Andrei,Bakulina, Olga,Dar'in, Dmitry,Guranova, Natalia,Krasavin, Mikhail
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- Three-Component Castagnoli-Cushman Reaction of 3-Arylglutaconic Acid Anhydrides, Carbonyl Compounds, and Ammonium Acetate: a Quick and Flexible Way to Assemble Polysubstituted NH-δ-lactams
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A practical straightforward synthesis of medicinally important NH-δ-lactams through the three-component Castagnoli-Cushman reaction of 3-arylglutaconic anhydrides with carbonyl compound and ammonium acetate has been developed. The scope of the protocol has been thoroughly explored paying particular attention to the carbonyl component using wide array of aliphatic and aromatic aldehydes as well as rarely involved cyclic and acyclic ketones. Synthetic potential of prepared compounds was demonstrated by a series of post-modifications, including unexpected isomerization.
- Peshkov, Anatoly A.,Bakulina, Olga,Dar'in, Dmitry,Kantin, Grigory,Bannykh, Anton,Peshkov, Vsevolod A.,Krasavin, Mikhail
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- Carboxylative Cyclization of 2-Butenoates with Carbon Dioxide: Access to Glutaconic Anhydrides
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Cyclic anhydrides are versatile synthons and functional comonomers. Herein, we reported an organic base-promoted carboxylative cyclization of 2-butenoates with carbon dioxide to produce important glutaconic anhydrides in good yields. This metal-free react
- Zhang, Ke,Zhang, Wen-Zhen,Tao, Xue-Yan,Zhang, Min,Ren, Wei-Min,Lu, Xiao-Bing
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p. 11579 - 11588
(2020/10/12)
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- Method for synthesizing pentene dianhydride compound by using carbon dioxide
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The invention belongs to the technical field of fine chemical synthesis, and relates to a method for synthesizing a pentene dianhydride compound by using carbon dioxide. The method comprises the following steps: using a 2-butenoic acid derivative as a raw material; adding an organic alkali and a reaction solvent, introducing carbon dioxide, stirring at 0-50 DEG C to react for 0.5-24 hours, standing to room temperature after the reaction is finished, slowly releasing unreacted gas, directly concentrating the reaction solution under reduced pressure to obtain a crude product, and carrying out column chromatography or recrystallization purification to obtain the pentene dianhydride product. According to the method, the 2-butenoic acid derivative and carbon dioxide which are cheap and easily available are used as raw materials, organic alkali is used as an accelerant, and the method is safe and simple to operate, low in toxicity and environment-friendly and has potential application valuein fine organic synthesis of medicines, pesticides and the like.
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Paragraph 0039-0040
(2020/06/02)
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- Catalytic asymmetric tamura cycloadditions
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In the presence of a novel, tert-butyl-substituted squaramide-based catalyst, enolizable anhydrides react with alkylidene oxindoles to generate spirooxindole products of significant synthetic interest with excellent enantio- and diastereocontrol. The methodology is of wide scope and encompasses both homophthalic and glutaconic anhydride derivatives, which lead to structurally diverse products. Glutaconic acid-derived anhydrides undergo a clean post-cyclization decarboxylation process which is not a feature of reactions involving homophthalic acid-derived anhydrides. The unusual influence of reaction temperature on diastereocontrol has been probed, with reactions occurring at 30 °C and -30 °C delivering products epimeric at one stereocenter only, in near optical purity. Squared away: The first strategy for bringing about enantioselective Tamura reactions is reported. In the presence of a squaramide-based catalyst, enolizable anhydrides react with alkylidene oxindoles to generate spirooxindole products with excellent enantio- and diastereocontrol. The methodology is of wide scope and leads to structurally diverse products.
- Manoni, Francesco,Connon, Stephen J.
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p. 2628 - 2632
(2014/03/21)
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- SYNTHESIS OF SUBSTITUTED BENZENOIDS AND BIPHENYLS VIA DIELS-ALDER CYCLOADDITION OF 6-METHOXY-2-PYRONES
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A convenient synthesis of substituted 6-methoxy-2-pyrones from alkyl and aryl esters is described.These pyrones undergo Diels-Alder reactions with acetylenic dienophiles to provide an efficient route to polysubstituted benzoates, phthalates and biphenyls.
- Ahmed, Salman A.,Bardshiri, Esfandiar,Simpson, Thomas J.
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p. 1595 - 1596
(2007/10/02)
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