- N -Heterocyclic carbene (NHC) catalyzed amidation of aldehydes with amines via the tandem N -hydroxysuccinimide ester formation
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A facile method for the amidation of aldehydes by a cascade approach was developed. This methodology, reported for the first time, uses a N-heterocyclic carbene (NHC) as the catalyst, and N-hydroxysuccinimide (NHS) mediated synthesis of amides utilising TBHP as the oxidant. Various substituted aldehydes reacted smoothly with NHS giving the corresponding active esters in moderate to good yields, which facilely converted into amides in one pot. In addition, the drug moclobemide was synthesized to represent the practical utility of the developed methodology. This journal is
- Singh, Ashmita,Narula
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supporting information
p. 7486 - 7490
(2021/05/13)
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- IBX-mediated oxidative addition of isocyanides to cyclic secondary amines: Total syntheses of alangiobussine and alangiobussinine
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The present study describes a robust and general method for the synthesis of C(1)-carboxamides through IBX-mediated oxidative addition of isocyanides to tryptolines and 1,2,3,4-tetrahydroisoquinolines. In this transformation, IBX plays a dual role of an oxidant and Lewis acid to activate imine facilitating isocyanide addition. Detailed mechanistic investigations were performed by isotopic labeling and real-time NMR experiments. The method was utilized for the gram scale syntheses of two alkaloids alangiobussine and alangiobussinine in 63% and 45% overall yield, respectively.
- Ambule, Mayur D.,Tripathi, Shashank,Ghoshal, Anirban,Srivastava, Ajay K.
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supporting information
p. 10872 - 10875
(2019/09/16)
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- Synthesis and anticancer activity of focused compound libraries from the natural product lead, oroidin
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Oroidin (1), (E)-N-(3-(2-amino-1H-imidazol-4-yl)allyl)-4,5-dibromo-1H- pyrrole-2-carboxamide, is a pyrrole alkaloid isolated from the marine sponge Agelas oroides. Routine screening in a panel of twelve cancer cell lines revealed 1 to be poorly cytotoxic with the 50% growth inhibition concentration (GI50) of 42 μM in MCF-7 (breast) cells and 24 μM in A2780 (ovarian) cells and >50 μM in all other cell lines tested. The development of eight focused libraries comprising thirty compounds total identified N-(biphenyl-4-ylmethyl)-1H-pyrrole-2-carboxamide (4l), N-benzyl-4,5-dibromo-1H- pyrrole-2-carboxamide (5a) and N-(biphenyl-4-ylmethyl)-4,5-dibromo-1H-pyrrole-2- carboxamide (5l) as potent inhibitors of cell growth in our panel of cell lines. Of these compounds GI50 values of 5 μM were observed with 4l against HT29 (colon) and SW480 (colon); 5a against HT29; and 5l against HT29, SW480, MCF-7, A431 (skin), Du145 (prostate), BE2-C (neuroblastoma) and MIA (pancreas) cell lines. As a cancer class, colon cancer appears to be more sensitive to the oroidin series of compounds, with analogue 5l being the most active.
- Dyson, Lauren,Wright, Anthony D.,Young, Kelly A.,Sakoff, Jennette A.,McCluskey, Adam
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p. 1690 - 1699
(2014/03/21)
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- Selective synthesis of N-substituted pyrrolo[1,2-a]pyrazin-1(2H)-one derivatives via alkyne cyclization
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A novel and efficient synthesis of N-substituted pyrrolo-pyrazinone derivatives has been developed. A trichloroacetyl group connected to the pyrrole ring was converted into the desired carboxamide derivatives. Promoted by NaH, the pyrrole carboxamide derivatives underwent a tandem reaction with propargyl bromide to afford pyrrolo-pyrazinones with high efficiency under very mild conditions. The mechanism for the formation of the products is discussed and supported by DFT calculations.
- ?etinkaya, Yasin,Balci, Metin
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supporting information
p. 6698 - 6702
(2014/12/11)
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- Direct synthesis of amides from coupling of alcohols and amines catalyzed by ruthenium(II) thiocarboxamide complexes under aerobic conditions
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Four octahedral ruthenium(II) thiocarboxamide complexes of the general formula [RuClCO(AsPh3)2(L)] (L = N-substituted pyridine-2-thiocarboxamide) incorporating carbonyl and triphenylarsine have been synthesized from the reaction of 1 equiv of ruthenium precursor [RuHClCO(AsPh3)3] with 1 equiv of thiocarboxamide ligands in refluxing ethanol in the presence of base. All the new complexes have been fully characterized by means of elemental analysis, IR, UV-vis, and NMR spectral methods. Molecular structures of all the complexes were determined by X-ray crystallography, which confirm the coordination mode of thiocarboxamide and reveal the presence of a distorted octahedral geometry around the Ru ion. All the ruthenium(II) thiocarboxamide complexes were generated as highly efficient catalysts for synthesis of secondary or tertiary amides by coupling of amines and alcohols with low catalyst loading, and the maximum yield was obtained up to 97%. The coupling reaction can be readily carried out under mild aerobic conditions, and release of water is the only byproduct. Further, the effect of substituents of the ligand, solvents, reaction temperature, time, and catalyst loading on the catalytic activity of the complexes has been investigated. A plausible mechanism is proposed for the synthesis of amides via hemiaminal as intermediate through an oxidation of an alcohol to aldehyde.
- Sindhuja, Elangovan,Ramesh, Rengan,Balaji, Sundarraman,Liu, Yu
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p. 4269 - 4278
(2014/12/09)
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- Simple, potent, and selective pyrrole inhibitors of monoamine oxidase types A and B
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N-Benzyl- and N-propargyl-1H-pyrrole-2-carboxyamides and some related methylenamines were synthesized and tested for their monoamine oxidase types A and B inhibitory activity. 2-(N-Methyl-N-propargylaminomethyl)-1H-pyrrole (24) was the most potent MAO-A inhibitor of the series [Ki(MAO-A) = 0.0054 μM], but it was not selective. Inhibitors N-4-fluorobenzyl-1H-pyrrole-2-carboxamide (12) and N-cyclohexylmethyl-1H-pyrrole-2-carboxamide (25) showed the highest MAO-A selectivity indexes (SI) corresponding to 2025 and > 2500, respectively, while 2-(N-methyl-N-benzylaminomethyl)-1H-pyrrole (21) was the most selective MAO-B inhibitor, having an SI of 0.0057.
- Silvestri, Romano,La Regina, Giuseppe,De Martino, Gabriella,Artico, Marino,Befani, Olivia,Palumbo, Marianna,Agostinelli, Enzo,Turini, Paola
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p. 917 - 920
(2007/10/03)
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