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991.
992.
Tran Thi-Minh-Dinh Duong Thuc-Huy Tran Thanh-Nha Nguyen Thi-Hang Nguyen Ngoc-Phuong Nguyen Ngoc-Hong Dinh Minh-Hiep Nguyen Thi-Anh-Tuyet 《Chemistry of Natural Compounds》2021,57(2):388-389
Chemistry of Natural Compounds - 相似文献
993.
Dr. Akira Matsumoto Bich-Ngoc Nguyen Tsubasa Honda Dr. Ryu Sakamoto Dr. Xiao Huang Prof. Dr. Shigeyoshi Sakaki Prof. Dr. Keiji Maruoka 《化学:亚洲杂志》2021,16(4):282-286
This article describes the synthetic application of ketone-derived oxaziridines as alkyl radical precursors in copper-catalyzed Carbon-Carbon bond formation reactions. Experimental and computational studies indicate a free radical mechanism, where alkyl radicals are efficiently generated via cleavage of a Carbon-Carbon bond of oxaziridines. Acyclic and unstrained cyclic oxaziridines are applicable to the present radical process, allowing for the generation of various alkyl radicals with good functional group compatibility. 相似文献
994.
995.
Dung Nguyen Tien Thanh Do Minh Huong Nguyen Thi Thuy Phan Thi Hoan Nguyen Thi Thanh Dinh Thi Mai Van Trang Nguyen Son Ninh The 《Structural chemistry》2020,31(6):2435-2450
Structural Chemistry - Quinolone and isoquinolone alkaloids, which were found in the plant kingdom, are now potential antioxidants. In this case study, a quantum calculated procedure utilizing the... 相似文献
996.
Trung Le Hao Nguyen Dr. Lisa M. Perez Prof. Donald J. Darensbourg Prof. Marcetta Y. Darensbourg 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(9):3674-3678
With the goal of generating anionic analogues to MN2S2 ⋅ Mn(CO)3Br we introduced metallodithiolate ligands, MN2S22− prepared from the Cys-X-Cys biomimetic, ema4− ligand (ema=N,N′-ethylenebis(mercaptoacetamide); M=NiII, [VIV≡O]2+ and FeIII) to Mn(CO)5Br. An unexpected, remarkably stable dimanganese product, (H2N2(CH2C=O(μ-S))2)[Mn(CO)3]2 resulted from loss of M originally residing in the N2S24− pocket, replaced by protonation at the amido nitrogens, generating H2ema2−. Accordingly, the ema ligand has switched its coordination mode from an N2S24− cavity holding a single metal, to a binucleating H2ema2− with bridging sulfurs and carboxamide oxygens within Mn-μ-S-CH2-C-O, 5-membered rings. In situ metal-templating by zinc ions gives quantitative yields of the Mn2 product. By computational studies we compared the conformations of “linear” ema4− to ema4− frozen in the “tight-loop” around single metals, and to the “looser” fold possible for H2ema2− that is the optimal arrangement for binucleation. XRD molecular structures show extensive H-bonding at the amido-nitrogen protons in the solid state. 相似文献
997.
Dr. Thanh Binh Nguyen Dr. Tuan Minh Nguyen Dr. Pascal Retailleau 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(21):4682-4689
In this study, a very simple technique to perform efficiently photodimerization of some vinylpyridines is reported. By irradiating a stirred mixture of several stilbazoles with solid oxalic acid dihydrate dispersed in a nonpolar (i.e., cyclohexane) or moderately polar (benzene, dichloromethane, dioxane) solvent, the corresponding dimeric cyclobutane adducts were obtained in high yields and excellent regio- and stereoselectivities. The strategy could also be applied successfully to oily, waxy, or even insoluble stilbazoles. Moreover, the oxalic acid loading could be lowered to substoichiometric amounts. When further optimizations were needed, our strategy was found to be highly flexible to identify other oligocarboxylic acids as alternative additives to improve, or even overturn, the regioselectivity. Oxalic acid and other oligocarboxylic acids were found to be capable of orienting more than 50 stilbazoles toward photodimerization under these conditions. 相似文献
998.
Woo‐Jin Yoo Junpei Kondo Jos A. Rodríguez‐Santamaría Thanh V. Q. Nguyen Sh Kobayashi 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(20):6844-6847
A facile synthetic procedure for the preparation of α‐trifluoromethyl carboxylic acids and esters was achieved through multicomponent coupling reactions between gem‐difluoroalkenes, cesium fluoride, and carbon dioxide. The products were generated in moderate to excellent yields, and the synthetic utility of this method was demonstrated through the preparation of trifluoromethylated versions of popular nonsteroidal anti‐inflammatory drugs (NSAIDs). 相似文献
999.
Analytical expressions of the exciton-exciton interaction in 3D and 2D laser-excited semiconductors are approximately derived in rather easy-to-handle forms which enable us to study in detail their dependences on the exciton momenta, the momentum transferred between two excitons and the electron-hole mass ratio.We would like to thank Prof. Nguyen Van Hieu and Prof. Dao Vong Due for their support given to us in the research of highly excited media. 相似文献
1000.
M. Wintenberger J. Dugue M. Guittard Nguyen Huy Dung Vo Van Tien 《Journal of solid state chemistry》1987,70(2)
The two isomorphous compounds LaCrOS2 and LaCrOSe2 are ferromagnetic (Tc = 35 and 51 K, respectively). This implies ferromagnetic super-superexchange interactions. NdCrOS2 is antiferromagnetic (TN = 72 K) and undergoes a spin-flop transition (Hc = 54 KOe at 20 K). The study of the thermal variation of Cr3+ and Nd3+ magnetic moments below TN allows a rough estimate of the Cr---Nd and Cr---Cr exchange fields ratio (0.1). 相似文献