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971.
《Analytical letters》2012,45(2):445-456
Abstract The ternary complexes of copper (II) with glycine, alanine, aspartate or glutamate as primary ligand and pyruvate as secondary ligand have been investigated using differential pulse polarography. the reversible diffusion controlled reduction of the complexed ion reveals two mixed complexes to be formed with stoichiometries 1:1:1 and 1:2:1. Their overall formation constants in a sodium perchlorate supporting electrolyte have been calculated at μ =0.1 and 25°C. 相似文献
972.
973.
Prof. Dr. Katsuhiro Isozaki Tomoya Yokoi Ryota Yoshida Dr. Kazuki Ogata Dr. Daisuke Hashizume Dr. Nobuhiro Yasuda Prof. Dr. Koichiro Sadakane Prof. Dr. Hikaru Takaya Prof. Dr. Masaharu Nakamura 《化学:亚洲杂志》2016,11(7):1076-1091
Two (ONO pincer)ruthenium‐complex‐bound norvalines, Boc?[Ru(pydc)(terpy)]Nva?OMe ( 1 ; Boc=tert‐butyloxycarbonyl, terpy=terpyridyl, Nva=norvaline) and Boc?[Ru(pydc)(tBu‐terpy)]Nva?OMe ( 5 ), were successfully synthesized and their molecular structures and absolute configurations were unequivocally determined by single‐crystal X‐ray diffraction. The robustness of the pincer Ru complexes and norvaline scaffolds against acidic/basic, oxidizing, and high‐temperature conditions enabled us to perform selective transformations of the N‐Boc and C?OMe termini into various functional groups, such as alkyl amide, alkyl urea, and polyether groups, without the loss of the Ru center or enantiomeric purity. The resulting dialkylated Ru‐bound norvaline, n‐C11H23CO?l ‐[Ru(pydc)(terpy)]Nva?NH‐n‐C11H23 (l ‐ 4 ) was found to have excellent self‐assembly properties in organic solvents, thereby affording the corresponding supramolecular gels. Ru‐bound norvaline l ‐ 1 exhibited a higher catalytic activity for the oxidation of alcohols by H2O2 than parent complex [Ru(pydc)(terpy)] ( 11 a ). 相似文献
974.
975.
Jagannath Jadhav Sharanabasappa KhanapaureRajanikant Kurane Rajashri SalunkheGajanan Rashinkar 《Tetrahedron letters》2013
An unprecedented methodology for the facile synthesis of 2-substituted 3-cyano-4-azaindoles using modified Madelung synthesis is described. The methodology relies on acid and amine coupling under very mild conditions. 相似文献
976.
977.
978.
Yu-Yang Zhang Huixuan Chen Xiaoding Jiang Hao Liang Xuefeng He Yaqi Zhang Xiangmeng Chen Wenhuan He Yongsu Li Liqin Qiu 《Tetrahedron》2018,74(18):2245-2250
A Ni-catalyzed addition of arylboronic acids to isatins was first developed. The reaction, driven by Ni(acac)2 and dppp as the phosphine ligand, gave 3-aryl-3-hydroxy-2-oxindoles in up to 97% yield. Scopes of benzyl-protected isatins and arylboronic acids were examined. Substituted phenylboronic acids along with fused-ring and heterocyclic boronic acids reacted with isatins smoothly. Preliminary asymmetric catalysis was investigated as well, showing moderate enantioselectivity. The mechanism was also described. 相似文献
979.
Philippe Renaud Michle Gerster 《Angewandte Chemie (International ed. in English)》1998,37(19):2562-2579
The neglect of free radicals over the past few years has been overcome, and they are no longer only considered as interesting reactive intermediates with limited synthetic potential. New opportunities are opened up by performing radical reactions in the presence of Lewis acids. Rate enhancement of radical addition to olefins as well as stereochemical control of such reactions can be achieved in a unique manner. Recent examples of enantioselective radical reactions and perspectives for applications in catalysis are discussed. 相似文献
980.
Yanyan Zhang Wenjuan Zeng Feifei Jia Juan Ye Yao Zhao Qun Luo Zihua Zhu Fuyi Wang 《Surface and interface analysis : SIA》2020,52(5):256-263
Cisplatin has been clinically used for treatment of solid tumors such as non–small-cell lung cancer for decades. However, tumor resistance may be acquired with losing the antitumor activity of cisplatin. As cellular membrane is the first barrier that cisplatin has to overcome before its further action inside the cells, the membrane composition must play a vital role in the cisplatin uptake and excretion, which further influences cisplatin sensitivity. In this work, we applied time-of-flight secondary ion mass spectrometry (ToF-SIMS) surface analysis combined with principle component analysis to distinguish the differences of cell membrane composition between non–small-cell lung cancer cells (A549) and its cisplatin resistant counterpart A549/DDP cells. The decreased phosphatidylcholine content and more abundant cholesterol were observed in the drug resistant cell surfaces, indicating the decreased membrane fluidity of A549/DDP cells. Moreover, we further compared membrane composition of A549 and A549/DDP cells after being treated with different concentrations of cisplatin. A higher composition level of proteins was discovered on all groups of A549/DDP cell membranes. The altered surface chemistry of cellular membranes induced by cisplatin indicates the significance of membrane structures in the drug resistance, which deserves further investigations to this regard. 相似文献