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111.
The efficient formation of single-isomer, differentially halogenated alkenes and alkanes is described. These structures were generated by treatment of the appropriate alkyne or alkene with tetrabutylammonium iodide in refluxing dichloroethane. This process is highly selective as evidenced by control experiments using ICl. Treatment of the same alkenes and alkynes directly with iodine monochloride resulted in complex, inseparable mixtures of regio- and stereoisomers. Mechanistic studies indicated that the Bu4NI reaction most likely proceeded through the slow generation of ICl. Complexation of ICl with Bu4NI is also a key controlling element that leads to perfect regio-, chemo-, and stereoselectivity in these processes. 相似文献
112.
A convenient method of synthesizing tetrasubstituted olefins as single isomers is described. E-β-Chloro-α-iodo-α,β-unsaturated esters are first converted into the corresponding E-β-chloro-α,β-unsaturated esters using Suzuki–Miyaura coupling reactions with arylboronic acids and alkenylboronic acids. These transformations gave complete selectivity, and proceeded with substitution at the more activated α-iodide position. These compounds, isolated as single isomers, were then transformed into tetrasubstituted olefins by Suzuki–Miyaura couplings with arylboronic acids, alkenylboronic acids, and alkyl boranes to afford the corresponding tetrasubstituted olefins as single isomers. During this coupling process, it was discovered that the use of small ligands, such as PMe3 or PEt3, was critical for efficient coupling. The stereochemistry and regiochemistry of the products were unequivocally established using NMR methods. 相似文献
113.
114.
The preparation of a ketone with two long chain perfluoroalkyl groups is reported via the coupling reaction of a perfluorinated alkylzinc reagent and a perfluoro-acid chloride. This ketone has been investigated in the heterogeneous removal of heavy metals M2+ (M = Sn, Cd, Pb, Hg) and As5+ from aqueous solutions and removal of these metals from organic solvents using the unique thermomorphic properties of the fluorous ketone. In addition, a comprehensive 13C NMR study of one of the intermediates in the synthesis, 2H,2H,3H,3H-perfluoronanoic acid, has allowed the determination of all 1JC-F and 2JC-F coupling constants. Also reported is the crystal structure of the acid CF3(CF2)5CH2CH2CO2H. 相似文献
115.
Single isomer trisubstituted olefins were converted into allyl boron nucleophiles that were condensed with aldehydes to give products containing quaternary centers. The products were obtained in extremely high diastereomeric ratios, a reflection of the stereochemical integrity of the starting materials. 相似文献
116.
117.
J. F. Ogilvie 《光谱学快报》2013,46(8):1341-1354
The radial functions for potential energy and adiabatic and nonadiabatic effects in the forms of polynomials with coefficients cj, hj Li, hj X, gj Li and gj X of the reduced variable for internuclear distance z=2.(R-Re)/(R+Re) to various non-negative powers have been determined for the family of diatomic molecules of the lithium halides, LiF, LiCl, LiBr and LiI, with the corresponding results of LiH included for purposes of comparison. Trends are evident in the coefficients of lower order, but those of higher order are susceptible not only to the influence of the extent and quality of the data but also to the truncation of the power series in the representations. The various radial functions are valid with the specified ranges of internuclear distance depending on the maximum extent of vibrational excitation of the spectra. 相似文献
118.
Christiane Yoakim Nathalie Goudreau GrahamA. McGibbon Jeff O'Meara PeterW. White WilliamW. Ogilvie 《Helvetica chimica acta》2003,86(10):3427-3444
A novel series of inhibitors of the HPV11 E1? E2 protein? protein interaction was identified. These inhibitors, which were discovered as a result of high‐throughput screening, feature an indandione system spiro‐fused onto an appropriately substituted tetrahydrofuran ring. Early stability studies indicated, surprisingly, that this particular series of compounds were readily converted, in binding assay buffer, to the corresponding carboxylates. NMR and mass spectrometry techniques were used to elucidate the structures of these products and the mechanism by which they are produced. 相似文献
119.
The object of the study was to design a tool for the purpose of cutting, loosening and redepositing a sufficient soil volume to be mixed with a specified quantity of organic waste slurry such that the slurry would be completely covered. Laboratory tests were conducted to determine the best tool shape for this function and to minimize the draft force required in operation. The results of full scale field tests are also shown, including the comparison of draft force measurements with values predicted from mechanics theory. 相似文献
120.
Sheng‐Lung Chou Jen‐Iu Lo Yu‐Chain Peng Meng‐Yeh Lin Hsiao‐Chi Lu Bing‐Ming Cheng J. F. Ogilvie 《ChemInform》2016,47(4):no-no
Photolysis of B2H6 dispersed in solid neon with far‐UV light (120—220 nm) at 3 K leads to the formation of B2H4, which is characterized by IR spectroscopy and B3LYP quantum chemical computations. 相似文献