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11.
Six new 4″-benzyloxyimino-4″-deoxyavermectin Bla derivatives were synthesized from avermectin Bla by the selective protection of C-5-hydroxy group,oxidation of C-4″-hydroxy group,and deprotection followed by reaction with O-substituted hydroxylamine hydrochlorides.Their structures were confirmed by IR,~1H NMR,~(13)C NMR and MS.Insecticidal activities of the derivatives against Phopalosiphum pseudobrassicae,Spodoptera exigua and Pluteua xylosteua were evaluated. 相似文献
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TU Shu-Jianga② WANG Qiana ZOU Xianga b SHI Fenga MIAO Chun-Baoa FANG Fanga XU Jia-Ninga a 《结构化学》2005,24(3):255-258
1 INTRODUCTION 1,4-Dihydropyridines (1,4-DHPs) are well-knowncompounds because of their pharmacological pro-perty as calcium channel modulators[1, . The che- 2]mical modifications, such as the introduction of dif-ferent substituents[3, or heteroatoms[5], of the DHP 4]ring have allowed the expansion of researches onthe structure-activity relationship to gain new in-sights into the molecular interactions at the receptorlevel. In fact, it is well established th… 相似文献
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Formation and Structure of [Al_(13)(μ_3-OH)_6(μ_2-OH)_6(μ_2-OH)_(12)(H_2O)_(24)]Cl_(15)·13H_2O 总被引:1,自引:0,他引:1
1 INTRODUCTION At present, the polyaluminium compounds are mainly studied by single-crystal X-ray diffraction method to obtain the components, structures and exis- tence forms of aluminium in hydrolysis system, and then hydrolysis courses and mechanisms of each hydrolytic polyaluminium cation could be further dis- closed[1~5]. Generally, the single crystals suitable for X-ray diffraction are obtained from the crystallization of polyaluminium cations into sulfates or selenates. Following … 相似文献
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1INTRODUCTIONPolarizedketenedithioacetalshavebeenex-tensivelyusedasbuildingblocksinorganicsyn-thesis,especiallyinthesynthesisofheterocycliccompounds[1~6].Pyrazoleanditsderivativesrepre-sentoneofthemostactiveclassesofcompoundspossessingwidespectraofbiologicalactivities.Overthepastfewyears,considerableevidenceshavebeenaccumulatedtodemonstratetheefficacyofpyrazolederivatives,suchasantibacterial[7],fun-gicidal[8],herbicidal[9],insecticidal[10]andotherbiologicalactivities[11,12].Uptonow,alarg… 相似文献
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1 INTRODUCTION Recently, the low-spin square-planar nickel(II) complexes and high-spin octahedral nickel(II) complexes with Schiff base ligands have received much attention in optical materials[1~3]. Some nic- kel(II) complexes are widely used as lubricating oil, rubber industry additives, a fire-resistant additive and fungicide for leather[4~7]. Also, their adducts with nitrogen have attracted broad attention due to their potential applications as organic conductors and magnetic mate… 相似文献
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1 INTRODUCTION Late-transition metal complexes as catalysts for ethylene oligomerization and polymerization have become an intense research subject[1]. Nickel com- plexes are in hot point due to the significant achieve- ments of academic research[2, 3] and industrial appli- cations[4, 5]. The nickel complexes with bidentate [P,O] ligands were industrialized as the SHOP pro- cess for α-olefins[4]. It is supposed that late transition metal complexes have a strong propensity of under- goi… 相似文献
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ZHAO Hui-Minga YUAN Li-Xiaa YANG Guo-Yinga SUN De-Shengb WANG Zun-Yaoa② CHI Qing-Qinga a 《结构化学》2006,25(10):1280-1286
1 INTRODUCTION Interhalogen compounds have played an impor- tant role in environment and chemical engineering production. During the course of ozone exhaustion induced by sunlight in polar region, Br2, BrCl and HOBr are all precursors of Br atom[1]. Lately, scien- tists have detected that the content of BrCl in polar region sunlight was 35 ppt, larger than that of Br2 (25 ppt). Previous studies suggested that the con- centration of BrCl and O3 exhibits obvious negative correlation: w… 相似文献
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1 INTRODUCTION In the past decades, metal disulphides have recei- ved much attention due to their diversity struc- tures[1~4] and applications as potential ligands for metal ions in biological system[5]. Metal disulfide compounds are usually prepared from the direct reactions of metal ions with organic disulphide[1~5], while some others are isolated from the reactions of metal salts and thiolates with the presence of certain oxidizing agents (e.g., O2, H2O2, etc.)[6, 7]. A large number o… 相似文献