排序方式: 共有14条查询结果,搜索用时 8 毫秒
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1.IntrodnctionWegiveaproofofthestrongconvergenceinofthesolutionoftheparabolicapproximationtowardstheentropicsolutiontothescalarconservationlawwhereuo(RN),udenotessomeapproximationofuosuchthatandthefluxfsatisfiesTheconvergenceoftheapproximatesolutions... 相似文献
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Hernando A. Trujillo Wendy M. Simon Erin T. Pelkey Gordon W. Gribble Jerry P. Jasinski 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(3):386-388
In the isomeric compounds 2‐benzyl‐3‐methyl‐1‐phenylbenzo[b]furo[2,3‐c]pyrrole and 2‐benzyl‐1‐methyl‐3‐phenylbenzo[b]furo[2,3‐c]pyrrole, both C24H19NO, the pyrrole ring, although presumably somewhat strained, does not differ appreciably from N‐methylpyrrole except for a relatively short C—C single bond in the pyrrole ring. 相似文献
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In this article, we introduce the concept of lacunary statistical convergence of order α of real number sequences and give some inclusion relations between the sets of lacunary statistical convergence of order α and strong Nαθ(p)-summability. Furthermore, some relations between the spaces Nαθ(p) and Sαθare examined. 相似文献
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Greger JG Yoon-Miller SJ Bechtold NR Flewelling SA MacDonald JP Downey CR Cohen EA Pelkey ET 《The Journal of organic chemistry》2011,76(20):8203-8214
A regiocontrolled synthesis of unsymmetrical 3,4-diaryl-3-pyrrolin-2-ones has been achieved in three steps from 1,2-diaryl-1-nitroethenes with pyrrole-2-carboxamides (pyrrole Weinreb amides) serving as the key linchpin intermediates. Two different methods for the preparation of the requisite nitroalkenes were investigated: (1) modified Henry reaction between arylnitromethanes and arylimines; and (2) Suzuki-Miyaura cross-coupling reaction of 2-aryl-1-bromo-1-nitroethenes with arylboronic acids. Some difficulty was encountered in the preparation of arylnitromethanes, thus leading to the exploration of a cross-coupling strategy that proved more useful. A Barton-Zard pyrrole cyclocondensation reaction between 1,2-diaryl-1-nitroethenes and N-methoxy-N-methyl-2-isocyanoacetamide gave the corresponding pyrrole Weinreb amides, which were then converted into the desired 3-pyrrolin-2-ones in two steps. Overall, this method allowed for the construction of 3,4-diaryl-3-pyrrolin-2-ones with complete regiocontrol of the substituents with respect to the lactam carbonyl. The utility of this synthetic methodology was demonstrated by the preparation of eight unsymmetrical and symmetrical 3,4-diaryl-3-pyrrolin-2-ones including the N-H lactam analogue of the selective COX-II inhibitor, rofecoxib. 相似文献
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Gordon W. Gribble Erin T. Pelkey Wendy M. Simon Hernando A. Trujillo 《Tetrahedron》2000,56(52):10133-10140
The unsymmetrical mesoionic münchnones 13 (3-benzyl-2-methyl-4-phenyl-1,3-oxazolium-5-olate) and 14 (3-benzyl-4-methyl-2-phenyl-1,3-oxazolium-5-olate) react with the N-protected 2- and 3-nitroindoles 1 (ethyl 2-nitroindole-1-carboxylate), 6 (3-nitro-1-(phenylsulfonyl)indole), and 17 (ethyl 3-nitroindole-1-carboxylate) in refluxing THF to afford in good to excellent yields the pyrrolo[3,4-b]indoles 15 (2-benzyl-1-methyl-3-phenyl-4-carboethoxy-2,4-dihydropyrrolo[3,4-b]indole), 16 (2-benzyl-3-methyl-1-phenyl-4-carboethoxy-2,4-dihydropyrrolo[3,4-b]indole), 18 (2-benzyl-1-methyl-3-phenyl-4-(phenylsulfonyl)-2,4-dihydropyrrolo[3,4-b]indole), and 19 (2-benzyl-3-methyl-1-phenyl-4-(phenylsulfonyl)-2,4-dihydropyrrolo[3,4-b]indole). In several cases the regiochemistry, which is opposite to that predicted by FMO theory, is very high and leads essentially to a single pyrrolo[3,4-b]indole; e.g., 6+13→19 in 74% yield. 相似文献
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[reaction: see text] Nine fluorescently labeled structurally varied polyguanidino dendrimers based on diamino acid monomeric units were individually synthesized in an efficient, scalable sequence using a trifluoroacetamide protecting group-perguanidinylation strategy. While the dendrimers varied significantly in their ability to enter a human lymphocyte cell line, the best transporters out-performed an oligoarginine reference standard. 相似文献
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[reaction: see text]. Short oligomers of arginine function as remarkably efficient molecular transporters of drugs and probe molecules into cells and tissue. Currently, these compounds are prepared on resin through a unidirectional solid-phase synthesis. To extend the utility of these compounds for therapeutic and research applications, a scalable solution-phase synthesis of Arg8 (1) has been developed on the basis of a segment doubling strategy that proceeds in 13 steps and 28% overall yield from 4, including a novel one-step perdeprotection-perguanidinylation reaction. 相似文献
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Wendy M. Simon Hernando A. Trujillo Erin T. Pelkey Gordon W. Gribble Jerry P. Jasinski 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):461-462
Crystal structure determination of the title molecule, C30H24N2O2S, reveals that the pyrrole ring in this fused heterocycle, although presumably strained and reactive in cycloaddition reactions, does not differ appreciably from N‐methylpyrrole except for a shorter C—C single bond [1.409 (4) Å] in the pyrrole ring. 相似文献