- Aerobic oxidation of primary amines to amides catalyzed by an annulated mesoionic carbene (MIC) stabilized Ru complex
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Catalytic aerobic oxidation of primary amines to the amides, using the precatalyst [Ru(COD)(L1)Br2] (1) bearing an annulated π-conjugated imidazo[1,2-a][1,8]naphthyridine-based mesoionic carbene ligand L1, is disclosed. This catalytic protocol is distinguished by its high activity and selectivity, wide substrate scope and modest reaction conditions. A variety of primary amines, RCH2NH2 (R = aliphatic, aromatic and heteroaromatic), are converted to the corresponding amides using ambient air as an oxidant in the presence of a sub-stoichiometric amount of KOtBu in tBuOH. A set of control experiments, Hammett relationships, kinetic studies and DFT calculations are undertaken to divulge mechanistic details of the amine oxidation using 1. The catalytic reaction involves abstraction of two amine protons and two benzylic hydrogen atoms of the metal-bound primary amine by the oxo and hydroxo ligands, respectively. A β-hydride transfer step for the benzylic C-H bond cleavage is not supported by Hammett studies. The nitrile generated by the catalytic oxidation undergoes hydration to afford the amide as the final product. This journal is
- Yadav, Suman,Reshi, Noor U Din,Pal, Saikat,Bera, Jitendra K.
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p. 7018 - 7028
(2021/11/17)
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- TYK2 INHIBITORS AND USES THEREOF
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The present invention provides compounds, compositions thereof, and methods of using the same for the inhibition of TYK2, and the treatment of TYK2-mediated disorders.
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Paragraph 00766-00767
(2020/06/19)
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- Process for synthesizing piracetam (by machine translation)
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The invention belongs to the field, and particularly relates to a novel process. The method comprises the specific steps: mixing glycinamide hydrochloride, phase transfer catalyst, alkali, controlling temperature dropwise adding 4 - chlorobutyryl chloride solution reaction, adjusting pH value, filtering, recycling solvent, solvent treatment residue, crystallization, drying and the like to obtain piracetam. The technological one-step reaction synthesis target compound, raw materials are cheap and easily available, the yield is high, the product quality is good, and the method is suitable for industrial production. (by machine translation)
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Paragraph 0051-0065
(2019/07/16)
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- Bifunctional organometallic catalysts for selective hydration of nitriles to amides
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In this report, we highlight our recent contributions towards the development of bifunctional catalysts for selective hydration of nitriles to amides.
- Singh, Kuldeep,Sarbajna, Abir,Bera, Jitendra K.
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p. 853 - 861
(2020/06/26)
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- Diversity-Oriented Synthesis of Heterocycles: Al(OTf)3-Promoted Cascade Cyclization and Ionic Hydrogenation
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An efficient and facile method has been developed for the diversity-oriented synthesis of heterocycles. Hexahydrophenoxazines, tetrahydroquinolines, indolines, hexahydrocarbazoles, and lactones were conducted via Al(OTf)3-promoted cascade cyclization and ionic hydrogenation. Furthermore, this protocol was utilized to smoothly prepare piracetam and its key intermediate as well.
- Liu, Tianqi,Jia, Wenqiang,Xi, Qiumu,Chen, Yonghui,Wang, Xiaojian,Yin, Dali
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p. 1387 - 1393
(2018/02/10)
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- Synthesis of substituted 2-(2-oxopyrrolidin-1-yl)acetamides
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The reaction of chloroacetamide with 2 equiv of γ-aminobutyric acid potassium salts provides a convenient method for the synthesis of substituted 4-[(2-amino-2-oxoethyl)amino]butanoic acids. Alkylation products of 2-aminoacetic and 3-aminopropanoic acid with chloroacetamide were isolated. Thermal cyclization of substituted 4-[(2-amino-2-oxoethyl)amino]butanoic acids afforded 2-(2-oxopyrrolidin-1-yl)acetamides.
- Kavina,Sizov,Yakovlev
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p. 873 - 878
(2017/08/02)
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- Ugi Four-Center Three-Component Reaction as a Direct Approach to Racetams
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We report the synthesis of racetams, a diverse class of small molecule drugs, by means of the Ugi four-center three-component reaction (U4C-3CR). For the first time, γ-aminobutyric acid is employed as bifunctional input in the Ugi reaction. This protocol is simple, general, and allows one-pot access to a range of drugs and bioactive small molecules.
- Cioc, R?zvan C.,Schaepkens van Riempst, Lola,Schuckman, Peter,Ruijter, Eelco,Orru, Romano V. A.
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p. 1664 - 1674
(2017/03/21)
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- Hemilability-Driven Water Activation: A NiII Catalyst for Base-Free Hydration of Nitriles to Amides
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The NiII complex 1 containing pyridyl- and hydroxy-functionalized N-heterocyclic carbenes (NHCs) is synthesized and its catalytic utility for the selective nitrile hydration to the corresponding amide under base-free conditions is evaluated. The title compound exploits a hemilabile pyridyl unit to interact with a catalytically relevant water molecule through hydrogen-bonding and promotes a nucleophilic water attack to the nitrile. A wide variety of nitriles is hydrated to the corresponding amides including the pharmaceutical drugs rufinamide, Rifater, and piracetam. Synthetically challenging α-hydroxyamides are accessed from cyanohydrins under neutral conditions. Related catalysts that lack the pyridyl unit (i.e., compounds 2 and 4) are not active whereas those containing both the pyridyl and the hydroxy or only the pyridyl pendant (i.e., compounds 1 and 3) show substantial activity. The linkage isomer 1′ where the hydroxy group is bound to the metal instead of the pyridyl group was isolated under different crystallization conditions insinuating a ligand hemilabile behavior. Additional pKa measurements reveal an accessible pyridyl unit under the catalytic conditions. Kinetic studies support a ligand-promoted nucleophilic water addition to a metal-bound nitrile group. This work reports a Ni-based catalyst that exhibits functional hemilability for hydration chemistry.
- Singh, Kuldeep,Sarbajna, Abir,Dutta, Indranil,Pandey, Pragati,Bera, Jitendra K.
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supporting information
p. 7761 - 7771
(2017/06/06)
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- Mild and selective heterogeneous catalytic hydration of nitriles to amides by flowing through manganese dioxide
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A sustainable flow chemistry process for the hydration of nitriles, whereby an aqueous solution of the nitrile is passed through a column containing commercially available amorphous manganese dioxide, has been developed. The product is obtained simply by concentration of the output stream without any other workup steps. The protocol described is rapid, robust, reliable, and scalable, and it has been applied to a broad range of substrates, showing a high level of chemical tolerance.
- Battilocchio, Claudio,Hawkins, Joel M.,Ley, Steven V.
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supporting information
p. 1060 - 1063
(2016/10/17)
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- A general and practical oxidation of alcohols to primary amides under metal-free conditions
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A general procedure for oxidation of both benzyl alcohols and alkyl alcohols to primary amides under catalyst free conditions has been developed. 34 examples of primary amides were produced from their corresponding alcohols in moderate to excellent yields. This is a practical procedure for primary amides synthesis; water and tert-butanol are the only by-products. A commercial drug, Piracetam, was prepared in one step with 73% yield as well.
- Wu, Xiao-Feng,Sharif, Muhammad,Feng, Jian-Bo,Neumann, Helfried,Pews-Davtyan, Anahit,Langer, Peter,Beller, Matthias
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p. 1956 - 1961
(2013/09/24)
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- POTENTIAL NOOTROPIC AGENTS: SYNTHESIS OF SOME (2-OXO-1-PYRROLIDINYL)ACETAMIDES AND SOME RELATED COMPOUNDS
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Ethyl (2-oxo-1-pyrrolidinyl)acetate was transformed by ester exchange to the 2-dimethylaminoethyl ester VI which was converted to the choline iodide ester VII.The mixed anhydride of (2-oxo-1-pyrrolidinyl)acetic acid and monoethyl carbonate was reacted with ethyl aminoacetate to give the ester VIII which was transformed on the one hand to the amide IX, and to the 2-dimethylaminoethyl ester X on the other.Reaction of the latter with methyl iodide afforded a further choline iodide ester XI.Reactions of (2-oxo-1-pyrrolidinyl)acetyl chloride with 4-chloroaniline and 3-aminopyridine gave the amides XII and XIV.The anilide XIII was obtained from 2-(2-oxo-1-pyrrolidinyl)butyric acid and 4-chloroaniline by means of dicyclohexylcarbodiimide.The benzo analogue (XV) of piracetam (I) was synthesized from oxindole via the ester XVI.The anilide XII (VUFB-16 536) was found to potentiate significantly the anticonvulsant effect of diazepam in mice, to prolong the survival time of mice under conditions of nitrogen anoxia, and to prolong significantly the duration of the "gasping reflex" in mice.
- Valenta, Vladimir,Holubek, Jiri,Svatek, Emil,Valchar, Martin,Krejci, Ivan,Protiva, Miroslav
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p. 2756 - 2764
(2007/10/02)
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