共查询到20条相似文献,搜索用时 593 毫秒
1.
Palladium-catalyzed Suzuki–Miyaura cross-coupling reaction of potassium pyridine-2-trifluoroborates and various aryl (heteroaryl) halides can generate the corresponding desired coupling products with moderate to good yields. It can be carried out under the conditions with ethanol as solvent, Pd(OAc)2 and SPhos as catalyst system and Na2CO3 as a base. 相似文献
2.
ZHANG Xinzhuang ZHEN Zhen & LIU Xinhou Technical Institute of Physics Chemistry of Chinese Academy of Sciences Beijing China 《中国科学B辑(英文版)》2005,48(4)
HNCO is a convenient photolytic source of NCO and NH radicals for laboratory kinetics studies of elementary reaction[1] and plays an important role in the combustion and atmosphere chemistry. It can re- move deleterious compounds rapidly from exhausted ga… 相似文献
3.
A method is described for the spectrophotometric determination of gold in the concentration range of 2 to 16 p.p.m. using phenyl-α-pyridyl ketoxime as the reagent. The reagent permits to detect Iμ of gold in I ml of a solution. The method is particularly free from interference by the ions with which gold is frequently associated. 相似文献
4.
LinKunAN XianZhangBU HaiQiangWU XinDongGUO LinMA LianQuanGU 《中国化学快报》2003,14(6):557-560
The reaction of cryptotanshinone and tanshinone IIA with several biogenic amine metabolites involved in the pathogenic pathways of HE were investigated and eight 1,2,3,4-tetrahydrophenanthrene derivatives,2-6 and 8-10,were obtained.The probable mechanism on reaction was discussed. 相似文献
5.
CrystalStructureofBis(3-hydroxy-2-pyridyl)disulfideChenXue-Tai;KangBei-Sheng;XuYong-Jin;HuYong-Han(StateKeyLaboratoryofStruct... 相似文献
6.
LI An-Rong CHEN Qing-YunShanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai China 《中国化学》1996,(6)
The addition reaction of difluorodiiodomethane (1) with alkenes in the presence of PdCl2(PPh3)2 or Pd(PPh3)4 afforded the corresponding iododifluoromethylated compounds in excellent yield. 相似文献
7.
A. N. Gusev V. F. Shul’gin M. A. Kiskin I. L. Eremenko 《Russian Journal of Coordination Chemistry》2011,37(8):589-593
The complex of silver(I) with the condensation product of benzaldehyde and 3-(pyridin-2-yl)-5-(2-aminophenyl)-1H-1,2,4-triazole (L), [AgL2]NO3 (I), was synthesized. The reaction of L with silver(I) nitrate was found to afford 2-(2′-pyridyl)-1,4-dihydro-5H-1,3,4-benzotriazepin-5-one along with complex I. The compounds synthesized were characterized by X-ray diffraction analysis. 相似文献
8.
A colorless monoclinic crystal of dichloro-benzoxazine was obtained and examined by single crystal X-ray diffraction analysis. At the same time, molecular modeling analysis of nine benzoxazine compounds with different substituting groups was performed. Both single crystal X-ray diffraction analysis and molecular modeling analysis provide a detailed picture of molecular structure on molecular level and show good consistence with each other. On the basis of structural analysis, the effects of molecular structure parameters on ring-opening polymerization of ben-zoxazines have been explored. 相似文献
9.
Hong Yu Tian Jie Zhang Bao Guo Sun Ming Quan Huang Jian Rong Li Xiao Xiang Han 《中国化学快报》2007,18(9):1049-1052
Isovaleraldehyde possesses malty,fruity,cocoa-like odor and is widely used in fruit,chocolate,coffee flavors.The preparation of natural isovaleraldehyde by the Maillard model reaction was studied in this paper.The effects of the ratio of D-glucose/L-leucine, reaction temperature and pH value on the yield of isovaleraldehyde were explored.The optimum conditions were as follows: n(D-glucose):n(L-leucine)=4,temperature 150℃,reaction time 3 h,pH 5.The highest yield of isovaleraldehyde obtained was about 32%. 相似文献
10.
TUNG Chen-Ho GUAN Jing-QuInstitute of Photographic Chemistry Chinese Academy of Sciences Beijing China 《中国化学》1996,14(6):541-548
The photochemical reactions of azobenzene (AB) incorporated into different solvent-swollen Nafion membranes were investigated. The location of azobenzene in water-swollen Nafion membranes was different from that in methanol-swollen Nafion membranes, which was responsible for the different photochemical reactions of AB. In methanol-swollen Nafion membranes only trans-cis isomerization took place, while in water-swollen Nafion membranes photochemical cyclization of AB occurred after rapid trons-cis isomerization. The relation between the relative quantum yields and the light intensity showed that the cyclization was a two-photo process. The numbers of AB molecules per cluster (nAB /cluster) in Nafion membranes with different AB concentrations and different water contents were calculated. Under the experimental condition two competitive photocyclization mechanisms were suggested by nAB /cluster in Nafion membranes, relative quantum yields of the cyclization, and the change of the ratio of benzidine to benz 相似文献
11.
Yu Chuan Li Si Ping Pang Yong Zhong Yu 《中国化学快报》2007,18(5):516-518
The cyclization reaction of D-aspartic acid was studied, the carboxyl groups of D-aspartic acid were protected by benzyl alcohol to give compound D-dibenzyl aspartate. Then (4R)-benzyl azetidine-2-one-4-carboxylate and meso-3,6-disubstituted piperazine- 2,5-diones were synthesized via intramolecular cyclization and intermolecular cyclization of D-dibenzyl aspartate, respectively, and their structures were confirmed by 1H NMR and MS. Both cyclization reaction conditions were also investigated in detail. 相似文献
12.
DU Da-Ming MENG Shuang-Ming WANG Yong-Mei MENG Ji-Ben ZHOU Xiu-ZhongDepartment of Chemistry Nankai University Tianjin China 《中国化学》1995,13(6):520-524
The solid state reactions of p-nitroacetophenone,acetyl-ferrocene with indole were catalyzed by anhydrous zinc chloride or aluminum chloride,and gave exclusively the 1:2 condensation products.The solid state condensation of aromatic ketones with l-phenyl-3-methyl-5-pyrazolone was also investigated,and the 1:1 and 2:1 condensation products were obtained.The structures of eleven new products were determined by IR,MS,1H NMR and elemental analysis. 相似文献
13.
《Journal of organometallic chemistry》1989,359(2):C57-C60
N-Substituted dialkynylimines react with η5-cyclopentadienyldicarbonylcobalt to give a mixture of η4-cyclobutadiene cobalt complexes, the structures of which have been determined by X-ray crystallography. 相似文献
14.
Αddition reactions of (1-methoxyalkyl)triphenylphosphonium ylides, derived from the corresponding Wittig salts and n-BuLi, to aldehydes were investigated. It was revealed that the betaine LiX complexes, the primary adducts, were converted to α-hydroxyketones, prior to the formation of oxaphosphetanes, by addition of aqueous NH4Cl at low temperature. 相似文献
15.
Ping Liu Junping Shi Yuwen Wang Xiuhong Feng 《Journal of mathematical chemistry》2013,51(8):2001-2019
Bifurcations of spatially nonhomogeneous periodic orbits and steady state solutions are rigorously proved for a reaction–diffusion system modeling Schnakenberg chemical reaction. The existence of these patterned solutions shows the richness of the spatiotemporal dynamics such as oscillatory behavior and spatial patterns. 相似文献
16.
Iwasaki Y Matsui R Suzuki T Nakazaki A Kobayashi S 《Chemical & pharmaceutical bulletin》2011,59(4):522-524
We have developed a high-yielding and stereoselective vinylogous Mukaiyama aldol reaction (VMAR) of α-haloenals. Contrary to the simple α,β-unsaturated aldehyde, α-haloenals were found to be reactive affording the corresponding VMAR adducts in excellent yields. Some transformations of VMAR adducts by Pd-mediated cross-coupling were also examined in order to demonstrate the synthetic utility of VMAR of α-haloenals. 相似文献
17.
LI Hongjun ZHU Tong DING Jie CHEN Qi & XU Bingye State Key Joint Laboratory of Environment Simulation Pollution Control College of Environmental Science Peking Uni- versity Beijing China 《中国科学B辑(英文版)》2006,49(4)
Sodium chloride is the major constituent of sea salt particles in atmospheric environment, with an esti- mated annual contribution of 1012 kg of sea salt parti- cles to the atmosphere[1]. Many studies have shown a significant chloride deficit in these particles when compared to bulk seawater[2,3]. This deficit has been attributed to reactions with NOx and SO2[4]. Simulta- neously, NO2 is one of the main pollutants of mobile vehicles. Reaction (1) may be particularly important to the atmosph… 相似文献
18.
Squareplanarcisdicarbonylrhodiumcomplex,aprecursorofcatalyticallyactivecompoundincatalyticreaction,isatypicalkindofcatalyst[1].Itisusuallyunstable.Forexample,withoutefficientprotectionofCOandhightemperature,diiododicarbonylrhodium,aneffectivecatalystforth… 相似文献
19.
When driven far from equilibrium,nonlinear chemical reactions often show a variety of self-organization behavior,including chemical oscillations,waves,chaos and patterns[1].Recently,the study of such nonlinear phenomena in‘complex’systems,such as the li… 相似文献
20.
No molecular ion peak from the Electron Impact lonization of eight co-hydroxyalkyltriphenyl phosphonium bromides(Ph3P (CH2)nOHBr-,n=2-6,8-10)can be found,except a part of some relative powerful fragment ions can be observed only.Each compound forms a very characteristic ion(O=PPbj-1) at m/z 277 through hydroxyl rearrangement reaction.The intensity of this ion is closely related with the size of the carbon chain of hydroxyalkyl and with temperature of ion source and temperature of sample probe.The above rearrangement reaction and the reaction to form ion at m/z 262 take place simultaneously,thus leading to strong competition.At n=2,ion at m/z 277 is the most powerful and becomes continuously the base peak.At n=3 and n=4,the intensity of ion at m/z 262 reaches the maximum,and is always the base peak,and the relative abundance of m/z 277 is only around 2%.At n=5,6,8,9,10,m/z 277 becomes base peak when the temperature of probe is below 300℃.But,when the temperature increases from 300℃to 350℃,m/z 262 sud 相似文献