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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101219-73-2 Influences of electronic effects and anions on the enantioselectivity in the oxazaborolidine-catalyzed asymmetric borane reduction of ketones

The influence of electronic effects on the enantioselectivity of the oxazaborolidine-catalyzed asymmetric borane reduction of ketones has been observed and investigated with use of parasubstituted acetophenones and propiophenones with a variety of functional groups and B-unsubstituted and B-methoxyoxazaborolidines derived from (S)-2-(diphenylhydroxymethyl)-pyrrolidine with borane and trimethyl borate as catalysts in toluene and THF. The results indicate that Hammett linear free energy electronic effects on the enantioselectivity in the asymmetric reduction were observed and rationalized. Tuning electronic effects of the catalyst can improve the enantioselectivity in the reduction. Another interesting finding to be noted is that anions heavily affect the enantioselectivity, especially for the B-methoxy catalyst, because of their coordination with the boron atom in the catalysts. https://www.lookchem.com/CASDataBase_101219-73-2.htm
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