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排序方式: 共有88条查询结果,搜索用时 15 毫秒
1.
Ravula Sharada Nukala Satheesh Kumar Thirukovela Narasimha Swamy Sirassu Narsimha Dasari Gouthami Kurma Srimathi Bandari Srinivas 《Russian Journal of General Chemistry》2022,92(4):702-708
Russian Journal of General Chemistry - In the current study, some new quinoxaline linked 1,3,4-oxadiazole sulfonamide hybrids have been designed, synthesized and characterized by IR, 1H and 13C... 相似文献
2.
JPC – Journal of Planar Chromatography – Modern TLC - The genus Justicia (Acanthaceae) is a source of important pharmaceutical compounds. Justicia species are integral parts of several... 相似文献
3.
Indoles undergo smooth alkylation with cyclopropyl ketones in the presence of the CeCl3·7H2O/LiI reagent system in refluxing acetonitrile under neutral conditions to produce the corresponding C-3 substituted indole derivatives in good to high yields and with high selectivity. The use of CeCl3·7H2O/LiI makes this method simple, convenient, and cost-effective. 相似文献
4.
Katritzky AR Nair SK Khokhlova T Akhmedov NG 《The Journal of organic chemistry》2003,68(14):5724-5727
Enynes 5a-g were prepared in moderate to good yields from 1-(triphenylphosphoranylideneaminoalkyl)benzotriazoles. Ring-closing metathesis of 5a-f afforded functionalized dienes 6a-f, respectively, which were used in a Diels-Alder cycloaddition reaction in the synthesis of the corresponding hexahydroisoquinoline derivatives 7a-f. 相似文献
5.
A general and efficient synthesis of sulfonylbenzotriazoles from N-chlorobenzotriazole and sulfinic acid salts 总被引:1,自引:0,他引:1
One-pot reactions of sulfinic acid salts (produced from organometallic reagents with SO2) with N-chlorobenzotriazole gave the corresponding N-alkane-, N-arene-, and N-heteroenesulfonylbenzotriazoles 3a-j in 41-93% yields. Reagents 3a-j are efficient sulfonylating agents, reacting at 20-80 degrees C with various primary and secondary aliphatic amines to yield the corresponding sulfonamides in 64-100% yields. 相似文献
6.
The role of solvent quality in determining the universal material properties of dilute polymer solutions undergoing steady simple shear flow is examined. A bead-spring chain representation of the polymer molecule is used, and the influence of solvent molecules on polymer conformations is modelled by a narrow Gaussian excluded volume potential that acts pairwise between the beads of the chain. Brownian dynamics simulations data, acquired for chains of finite length, and extrapolated to the limit of infinite chain length, are shown to be model independent. This feature of the narrow Gaussian potential, which leads to results identical to a delta-function repulsive potential, enables the prediction of both universal crossover scaling functions and asymptotic behavior in the excluded volume limit. Universal viscometric functions, obtained by this procedure, are found to exhibit increased shear thinning with increasing solvent quality. In the excluded volume limit, they are found to obey power law scaling with the characteristic shear rate beta, in close agreement with previously obtained renormalization group results. The presence of excluded volume interactions is also shown to lead to a weakening of the alignment of the polymer chain with the flow direction. 相似文献
7.
Epoxides react smoothly with tetraallyltin in the presence of 2 mol% of Bi(OTf)3 under mild reaction conditions to afford the corresponding homoallylic alcohols in excellent yields with high regioselectivity while aryl aziridines produce exclusively allyl amines in good yields under similar conditions. 相似文献
8.
Clay catalyzed Friedländer condensation of 2-amino arylaldehyde or ketone with carbonyl compounds containing α-methylene group has been achieved in solvent free condition under microwave irradiation to give polycyclic quinoline derivatives. 相似文献
9.
Paulson Mathew Satheesh K. Nair K. M. Sreedhar V. N. Rajasekharan Pillai 《合成通讯》2013,43(16):2157-2161
When α‐oxoketene dithioacetals 1a–n were treated with the bromine complex of a copolymer of 1‐vinyl‐2‐pyrrolidone and 4‐vinylpyridine, the corresponding thiolcarboxylates 2a–n were formed in excellent yields. The reaction also works with other 1‐vinyl‐2‐pyrrolidone‐derived polymers as well as commercially available polyvinylpyrrolidone–bromine complexes. The method is suitable for preparing aliphatic, aromatic, and γ,δ‐unsaturated β‐oxothiolcarboxylates. 相似文献
10.
Satheesh Chandran M Temina Mary Robert Sunitha K Dona Mathew C. P. Reghunadhan Nair 《先进技术聚合物》2014,25(8):881-890
This paper outlines the synthesis and characterization of O‐allyl aralkyl phenolic (O‐allyl Xylok, OAX) resins having low melt viscosity and its Alder‐ene blends with 2, 2′‐bis 4‐[(4′‐maleimido phenoxy) phenyl] propane. The blends manifested a three‐stage curing pattern that converged to a two‐stage pattern on enhancing the maleimide content. The polymerization kinetics of typical allyl and maleimide rich resin systems showed apparent activation energy increasing and pre‐exponential factor decreasing from ene to the Diels–Alder step. Increased allyl content improved mechanical and impact properties of the composites at ambient temperature, although it diminished the retention of interlaminar shear strength at elevated temperature. Increased maleimide content of the resin was conducive for the higher rigidity for the composite and its retention at elevated temperature. A substantial increase in Tg (from 153°C to 280°C) and thermal stability was observed with an increase in maleimide content. High allyl content resulted in improved mechanical properties thanks to better resin–reinforcement interaction as revealed from morphological analysis. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献