- A one-pot route to thioamides discovered by gas-phase studies: palladium-mediated CO2 extrusion followed by insertion of isothiocyanates
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A new palladium mediated “one pot” synthesis of thioamides from aromatic carboxylic acids (ArCO2H + RNCS → ArC(S)NHR + CO2) was discovered by gas-phase experiments and theoretical studies. Palladium-mediated decarboxylation of aromatic carboxylic acids followed by addition of substituted isothiocyanates leads to the corresponding thioamide derivatives.
- Noor, Asif,Li, Jiawei,Khairallah, George N.,Li, Zhen,Ghari, Hossein,Canty, Allan J.,Ariafard, Alireza,Donnelly, Paul S.,O'Hair, Richard A. J.
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- Palladium-Mediated CO2 Extrusion Followed by Insertion of Isocyanates for the Synthesis of Benzamides: Translating Fundamental Mechanistic Studies to Develop a Catalytic Protocol
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Mechanistic studies of a stoichiometric palladium-mediated ExIn (ExIn = extrusion-insertion) decarboxylative amidation of aromatic carboxylic acids are presented, providing gas-phase and condensed-phase spectroscopic data, as well as theoretical computational evidence for intermediates in a proposed stepwise process. The understanding gained from these mechanistic studies directed the development of a palladium-catalyzed procedure in which benzamides are obtained in good to high yields in a one-pot 30 min microwave irradiation assisted protocol. A combination of experimental data and DFT calculations reveals that certain ligand additives favor the selective formation of benzamides rather than the undesired protodecarboxylation side product.
- Canty, Allan J.,Donnelly, Paul S.,McKay, Alasdair I.,O'Hair, Richard A. J.,Yang, Yang
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- An efficient magnetic copper ferrite nanoparticle catalysed ligand and solvent free synthesis of N-aryl amide from aldoximes and iodobenzene
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A simple, efficient, and environmentally benign method has been reported for the synthesis of N-aryl amides using aldoximes and iodobenzene under ligand free and solvent free conditions and using magnetically separable copper ferrite nanoparticles as catalyst. The catalyst was characterised using XRD, FEG-SEM, EDAX, ICP-AES and TEM and tested for recyclability for up to five cycles.
- Sarode, Sachin A.,Bhojane, Jeevan M.,Nagarkar, Jayashree M.
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p. 105353 - 105358
(2015/12/30)
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- Benzylamide derivative compound attenuates the ultraviolet B-induced hyperpigmentation in the brownish guinea pig skin
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This study evaluated the effects of synthetic benzylamide compound I (2,6-dimethoxy-N-phenylbenzamide) on the ultraviolet B (UV B)-induced hyperpigmentation of the skin. UV B-induced hyperpigmentation was elicited on brownish guinea pig skin according to the method reported by Hideya et al. [Arch Dermatol Res 290 (1998) 375] with minor modifications. A lightening effect was observed following the topical application of compound I on UV-stimulated hyperpigmentation. The skin returned to its original color after treatment with compound I. Fontana-Masson staining indicated that melanin level in the hyperpigmented area was significantly decreased in the compound I-treated animals. However, the number of melanocytes were not changed in the compound I-treated groups using the S-100 stain, which is an immunohistochemical method. In vitro experiments using the cultured melanoma cells showed a 31.7% inhibition of melanin production by compound I at 100μM. In addition, this compound had no effect on the tyrosinase enzyme function. However, it exhibited a catalyzing effect on the dopachrome transformation into 5,6-dihydroxyindole-2-carboxylic acid. Overall, the pigment-lightening effects of the compound I may due to the dopachrome tautomerase stimulation.
- Choi, Sang Yoon,Kim, Sanghee,Hwang, Jae Sung,Lee, Byeong Gon,Kim, Hocheol,Kim, Sun Yeou
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p. 707 - 715
(2007/10/03)
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- NEW ACTIVATION OF CARBOXYLIC ACIDS BY REACTION WITH N,N-BIS-(2-OXO-3-OXAZOLIDINYL) PHOSPHORODIAMIDIC CHLORIDE (ClSPO)
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Pentacoordinated and quinquevalent phosphorus intermediates, have been isolated by reaction between the title reagent and carboxylic acids, prior to conversion into amides.
- Cabre-Castellvi, Juan,Palomo-Coll, Antonio Luis
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p. 4179 - 4182
(2007/10/02)
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