104-04-1 Microwave-assisted synthesis of amide under solvent-free conditions

An efficient and environmentally friendly synthetic method for the synthesis of primary amides under microwave irradiation was described, in which the primary amine was directly reacted with acid without any catalytic agents. The reaction took place in 8-12-min, which was much shorter than the traditional synthetic methods, with almost quantitative yields. The influential factor of the reaction was discussed. The tautomerization between the carboxylic acid group and the H atom in α-carbon of L-amino acid was observed, presumably a dehydrated intermediate forming from this tautomerized isomer. Copyright Taylor & Francis Group, LLC. https://www.lookchem.com/CASDataBase_104-04-1.htm

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1023-17-2 Syntheses, structures, and catalytic activity in Friedel–Crafts acylations of substituted tetramethylcyclopentadienyl molybdenum carbonyl complexes

Reactions of the substituted tetramethylcyclopentadienes [C 5 HMe 4 R] [R?=? t Bu, Ph, CH 2 CH 2 C(CH 3 ) 3 ] with Mo(CO) 3 (CH 3 CN) 3 in refluxing xylene gave a series of dinuclear molybdenum carbonyl complexes [(η 5 -C 5 Me 4 R)Mo(CO) 3 ] 2 [R?=? t Bu (1), Ph (2), CH 2 CH 2 C(CH 3 ) 3 (3)], [(η 5 -C 5 Me t Bu)Mo(μ-CO) 2 ] 2 (4)], and [(η 5 -C 5 Me 4 ) t Bu] 2 Mo 2 O 4 (μ-O) (5)], respectively. Complexes 1–5 were characterized by elemental analysis, IR, 1 H NMR, and 13 C NMR spectroscopy. In addition, their crystal structures were determined by X-ray crystal diffraction analysis. The catalytic activities of complexes 1–3 in Friedel–Crafts acylation in the presence of o-chloranil has also been investigated; the reactions were achieved under mild conditions to give the corresponding products in moderate yields. https://www.lookchem.com/CASDataBase_1023-17-2.htm
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7440-47-3 Influence of pulse plating on the crystal structure and orientation of chromium

Chromium deposits with various structures and orientations were prepared by pulse plating from a sulfate-catalyzed chromic acid solution and without formic acid addition. The influences of the puls duration, off-time, curent density, formic acid concentration, and plating time on the structure and orientation were studied by X-Ray diffraction and transmition electron microcsopy. https://www.lookchem.com/CASDataBase_7440-47-3.htm
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1792-81-0 Phenol and dihydroxybenzene hydrogenation catalysts based on polyamide dendrimers and rhodium species

Heterogeneous catalysts based on rhodium nanoparticles and first- and second-generation poly(amidoamine) (PAMAM) dendrimers crosslinked with hexamethylene diisocyanate have been synthesized. It has been found that catalyst samples with a particle size of 0.88 to 1.96 nm, depending on the PAMAM dendrimer generation, are effective in the hydrogenation of phenol, hydroquinone, resorcinol, and pyrocatechol (85°C, 30 atm O 2 , 2 h). In phenol hydrogenation, the selectivity for cyclohexanone is 100%. Cyclohexanone has not undergone further transformation under the reaction conditions. The main products of dihydroxybenzene hydrogenation have been trans-cyclohexanediols, with their proportion decreasing in the order: resorcinol > hydroquinone > pyrocatechol. The selectivity has been found to be 100% for 1,3-cyclohexanediol, 97-99% for 1,4-cyclohexanediol, and 33-91% for 1,2-cyclohexanediol. The catalysts based on the second-generation dendrimer have shown a high activity in dihydroxybenz...
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