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1.
Commercially available alpha-aminodiphenylmethane 1 (benzhydrylamine) serves as a convenient ammonia equivalent in the dimethyltitanocene-catalyzed intermolecular hydroamination of alkynes. The primary formed imines can be hydrogenated and cleaved directly to the corresponding primary amines by catalytic hydrogenation using Pd/C as catalyst. 相似文献
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Pineschi M Bertolini F Haak RM Crotti P Macchia F 《Chemical communications (Cambridge, England)》2005,(11):1426-1428
A conceptually new, simple and practical method for the syn-nucleophilic displacement of aryl and vinyl epoxides and aryl aziridines with (substituted) phenols, using aryl borates as activating nucleophiles under neutral conditions, is reported. 相似文献
4.
Subbiah Meenakshisundaram RM. Sockalingam 《Journal of molecular catalysis. A, Chemical》2000,160(2):269-275
Catalytic activity of Os(VIII) in the oxidation of some twenty organic sulfides with sodium salt of N-chlorobenzenesulfonamide (CAB) has been investigated in alkaline (pH8.7) t-butanol–water (1:1 v/v) medium. Significant retarding influence of [OH−] on the reactivity is exhibited. The catalysed reaction is strongly accelerated in the presence of Hg(II). Imperfections are observed in the linear Hammett relationship in the case of –NO2 substituents. 相似文献
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Nano titanium dioxide (nTiO2), generally considered to be toxicologically inert, is manufactured in large quantities and extensively applied in consumer products. The small size and large surface area endow them with an active group or intrinsic toxicity. Advances in instrumentation are making Raman spectroscopy the tool of choice for an increasing number of (bio) chemical applications. One of the great advantages of this technique is its ability to provide information on the concentration, structure and interaction of biochemical molecules in their microenvironments within intact cells and tissues, non-destructively. Zebrafish (Danio rerio), one of the most important vertebrate model organisms used in developmental biology, are increasingly used in biomedical research, particularly as a model of human disease. In the present work, an attempt is made to study the effect of titanium dioxide, both nano and bulk, on the microenvironment of the liver tissues of Zebrafish using FT-Raman spectroscopy. The results of the present study suggest that TiO2 exposure demonstrate a marked influence on the microenvironments of the liver tissues of Zebrafish. A shift to a higher wavenumber and an increase in the intensity of the band at ∼1087 cm−1 in the TiO2 exposed tissues suggest that some of the conformational changes resulting from the alkali recovery process takes place due to TiO2 exposure. The decreased intensity ratio (I3220/I3400) observed in the titanium-exposed tissues suggests a decreased water domain size, which could be interpreted in terms of weaker hydrogen-bonded molecular species of water in the TiO2 exposed tissues. The observed shift of COO− bands to higher frequencies shows the disruption of salt bridges as a result of a change in the oppositely charged partners and due to the enhanced random coil conformation. The variation in the intensity ratio of the tyrosyl doublet (I858/I825) indicates variation in the hydrogen bonding of the phenolic hydroxyl group due to TiO2 exposure. The results further suggest that the microenvironments are greatly altered due to titanium nano exposure when compared to titanium bulk. In conclusion, the results indicate that FT-Raman spectroscopy might be a useful tool for rapid assessment of nano particle biological interactions. 相似文献
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K. Spaargaren P. K. Korver P. J. Der Van Haak Th. J. de Boer 《Magnetic resonance in chemistry : MRC》1971,3(5):605-614
Amide-rotational barriers of a series of para-substituted N,N-dimethylbenzamides and -cinnamamides have been obtained by both the intensity ratio method, according to Rogers and Woodbrey,2 and an iterative total line shape analysis. From a comparison of the results, it is concluded that a discussion of rotational barriers obtained with the intensity ratio method should preferably be based on ΔG values, which are nearly equal for both methods, rather than on ΔG? at other temperatures. 相似文献
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P. K. Korver K. Spaargaren P. J. van der Haak Th. J. de Boer 《Magnetic resonance in chemistry : MRC》1970,2(3):295-302
Rotational barriers in 21 p- and m-substituted N,N-dimethylbenzamides in CDCl3 as solvent have been determined using the intensity ratio method of Woodbrey. These data compare very well with values from the literature1 obtained with a total line shape analysis. From structure-reactivity correlations evidence has been obtained for a relatively strong resonance interaction between the substituent in the aromatic ring and the partially double amide bond. 相似文献
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