- Electrochemical anion pool synthesis of amides with concurrent benzyl ester synthesis
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An electrosynthesis method for amide bond formation has been developed in an attempt to increase the atom economy for this class of reactions. This "anion pool" method electrochemically generates strong nucleophiles from amine substrates. The amine nucleophiles then react with acid anhydrides to generate amides, and the by-product from this reaction undergoes further chemical transformations to generate pharmaceutically relevant benzoic esters. These one-pot reactions are operationally simple, are performed at room temperature, and avoid rare transition metals and added bases. The amide synthesis is amenable to primary and secondary amines and a variety of anhydrides with yields up to 90% obtained. Atom economy and process mass index (PMI) values calculated for this procedure indicate that this process can be considered greener compared to traditional amide synthesis routes used by industry. Furthermore, this electrochemical approach showed unique selectivity when substrates that contained two inequivalent amine moieties were examined.
- Mevan Dissanayake,Melville, Alex D.,Vannucci, Aaron K.
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supporting information
p. 3165 - 3171
(2019/06/18)
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- Base-promoted amide synthesis from aliphatic amines and ynones as acylation agents through C-C bond cleavage
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A new protocol for the synthesis of amides via base-promoted cleavage of the C(sp)-C(CO) bond of ynones with aliphatic primary and secondary amines under transition-metal-, ligand-, and oxidant-free conditions has been developed. This method exhibits a wide substrate scope, high functional group tolerance and exclusive chemoselectivity, as well as mild reaction conditions.
- Cheng, Guolin,Lv, Weiwei,Kuai, Changsheng,Wen, Si,Xiao, Shangyun
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supporting information
p. 1726 - 1729
(2018/02/21)
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- HIGHLY CHEMOSELECTIVE REACTIONS IN PRESENCE OF AROMATIC AMINO GROUPS
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: The invention discloses a novel process for highly chemoselective reactions of substituted anilines without any detectable reaction at aromatic amino group. The invention also relates to a novel process for preparation of neostigmine methylsulphate via chemoselective reaction of 3-amionphenol and aryl dimethylcarbamates.
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Page/Page column 39; 40
(2017/11/06)
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- Ruthenium-catalyzed oxidative decyanative cross-coupling of acetonitriles with amines in air: A general access to primary to tertiary amides under mild conditions
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Catalyzed by Ru and in the presence of air and nucleophiles such as amines or ammonia, activation of the C-CN bond could be easily achieved under mild conditions to produce primary to tertiary amides in good to excellent yields. The use of accessible and functional-group-tolerant starting materials, a cheap, low-loading and recyclable catalyst, ligand-free conditions and excellent product yields are the advantages of the method. Moreover, compared with the Ritter reaction and hydration methods, this novel reaction has more comprehensive application scope.
- Wang, Yuguang,Wu, Zhongli,Li, Qin,Zhu, Bingchun,Yu, Lei
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p. 3747 - 3757
(2017/09/07)
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- Synthesis and Biological Evaluation of 2-Aminobenzothiazole and Benzimidazole Analogs Based on the Clathrodin Structure
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A series of 2-aminobenzothiazole and benzimidazole analogs based on the clathrodin scaffold was synthesized and investigated for their antimicrobial and antiproliferative activities as well as for their effects in hepatitis C virus (HCV) replicon model. Compound 7, derived from 2-aminobenzothiazole, exhibited moderate antimicrobial activity only against the Gram-positive bacterium, Enterococcus faecalis. In the antiviral assay, compounds 4d and 7 were found to suppress the HCV replicon by >70%, but also to exhibit cytotoxicity against the host cells (35 and 44%, respectively). Compounds 4a and 7 demonstrated good activity in the antiproliferative assays on the human melanoma cell line A-375. To assess the selectivity of the effects between cancerous and noncancerous cells, a mouse fibroblast cell line was used. The IC50 values for compound 7 against the melanoma cell line A-375 and the fibroblast cell line BALB/c 3T3 were 16 and 71 μM, respectively, yielding fourfold selectivity toward the cancer cell line. These results suggest that compound 7 should be studied further in order to fully explore its potential for drug development. A series of novel 2-aminobenzothiazole and benzimidazole derivatives based on the clathrodin structure was synthesized and evaluated for antimicrobial, antiproliferative and antiviral activities. (9H-Fluoren-9-yl)-methyl [(2-aminobenzo[d]thiazol-6-yl)methyl]carbamate 7 exhibited antiproliferative activity against the melanoma cell line A-375 (IC50 = 16 μM) with 4-fold selectivity between cancerous (A-375) and noncancerous (BALB/c 3T3) cells.
- Montalv?o, Sofia,Leino, Teppo O.,Kiuru, Paula S.,Lillsunde, Katja-Emilia,Yli-Kauhaluoma, Jari,Tammela, P?ivi
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p. 137 - 149
(2016/02/09)
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- Zirconium-catalyzed direct amide bond formation between carboxylic esters and amines
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Development of catalytic amide bond formation reactions from readily available starting materials remains a challenging task for modern organic chemistry. Herein, we report that unactivated carboxylic esters and amines react in the presence of 10 mol % of zirconocene dichloride (Cp2ZrCl2) in toluene at 110 °C to afford amides in very good to excellent conversions. The Zr-catalyzed reaction is amenable for the amidation of aliphatic and aromatic carboxylic esters with primary and secondary amines. The reaction proceeds with almost complete retention of configuration for chiral esters and chiral amines.
- Lenstra, Danny C.,Nguyen, D. Thao,Mecinovi?, Jasmin
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p. 5547 - 5553
(2015/08/03)
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- Tert -Butyl Peroxybenzoate Mediated Selective and Mild N-Benzoylation of Ammonia/Amines under Catalyst- and Solvent-Free Conditions
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A new protocol for the synthesis of amides from tert-butyl peroxybenzoate (TBPB) and ammonia/amines has been developed under catalyst- and solvent-free conditions. The ammonia, primary and secondary amines reacted smoothly with TBPB to furnish the corresponding primary, secondary, and tertiary amides in excellent yields. TBPB proved to be an efficient and highly chemoselective benzoylating reagent for aliphatic amines in the presence of aromatic amines/hydroxyl groups.
- Yadav, Dilip Kumar T.,Bhanage, Bhalchandra M.
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supporting information
p. 1862 - 1866
(2015/08/06)
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- Structure-based design and synthesis of the first weak non-phosphate inhibitors for IspF, an enzyme in the non-mevalonate pathway of isoprenoid biosynthesis
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In this paper, we describe the structure-based design, synthesis, and biological evaluation of cytosine derivatives and analogues that inhibit IspF, an enzyme in the non-mevalonate pathway of isoprenoid biosynthesis. This pathway is responsible for the biosynthesis of the C5 precursors to isoprenoids, isopentenyl diphosphate (IPP, 1) and dimethylallyl diphosphate (DMAPP, 2; Scheme 1). The non-mevalonate pathway is the sole source for 1 and 2 in the protozoan Plasmodium parasites. Since mammals exclusively utilize the alternative mevalonate pathway, the enzymes of the non-mevalonate pathway have been identified as attractive new drug targets in the fight against malaria. Based on computer modeling (cf. Figs. 2 and 3), new cytosine derivatives and analogues (Fig. 1) were selected as potential drug-like inhibitors of IspF protein, and synthesized (Schemes 2-5). Determination of the enzyme activity by 13C-NMR spectroscopy in the presence of the new ligands showed inhibitory activities for some of the prepared cytosine and pyridine-2,5-diamine derivatives in the upper micromolar range (IC50 values; Table). The data suggest that it is possible to inhibit IspF protein without binding to the polar diphosphate binding site and the side chain of Asp56′, which interacts with the ribose moiety of the substrate and substrate analogues. Furthermore, a new spacious sub-pocket was discovered which accommodates aromatic spacers between cytosine derivatives or analogues (binding to 'Pocket III') and rings that occupy the flexible hydrophobic region of 'Pocket II'. The proposed binding mode remains to be further validated by X-ray crystallography.
- Baumgartner, Corinne,Eberle, Christian,Diederich, Francois,Lauw, Susan,Rohdich, Felix,Eisenreich, Wolfgang,Bacher, Adelbert
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p. 1043 - 1068
(2008/03/13)
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- 1-(2,5-dichlorophenyl)-2,2-bis(methylsulfanyl)vinyl esters as highly efficient chemoselective acylating reagents
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1-(2,5-Dichlorophenyl)-2,2-bis(methylsulfanyl)vinyl esters 4f-k were prepared in yields usually greater than 90%, by reacting acyl chlorides with 1-(2,5-dichlorophenyl)-2,2-bis(methylsulfanyl)ethanone enolate. These esters were demonstrated to be excellent chemoselective reagents for the acylation of amines, alcohols, thiols, pyrrole and indole. From all the acylation reactions the dimethyl α-oxo dithioacetal 2d, recyclable for the preparation of esters 4f-k, could be recovered in 90-100% yield.
- Degani,Dughera,Fochi,Serra
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p. 1200 - 1208
(2007/10/03)
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- AROMATIC HYDROXYLATION OF BENZYLAMIDES BY POTASSIUM SUPEROXIDE
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N-benzylamides react with potassium superoxide in benzene in presence of 18-crown-6 ether to give ortho and para hydroxylated products.A mechanism is proposed for this reaction, involving the nucleophilic attack of superoxide anion to amide carbonyl and hydrogen abstraction from benzyle methylene by the substrate-superoxide adduct.
- Galliani, Guido,Rindone, Bruno
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p. 2313 - 2318
(2007/10/02)
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