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81.
82.
Dahai He Xuemin Xu Yan Zhou Wenlong Deng Bin Xia Lisheng Ding 《Helvetica chimica acta》2012,95(7):1136-1143
Two new diterpenoids, loxocalyxin A ( 1 ) and 13‐epiloxocalyxin A ( 2 ), and two new sesquiterpenoids, loxocalyxins B and C ( 3 and 4 , resp.), together with three known compounds, were isolated from the MeOH extract of the whole plant of Loxocalyx urticifolius Hemsl . The structures of the new compounds were established by means of spectroscopic analysis including one‐ and two‐dimensional NMR spectroscopy. All new structures were confirmed by X‐ray crystallographic analysis. Their absolute configurations were established. 相似文献
83.
84.
Jun‐Ju Xu Da‐Ke Zhao Hong‐Lian Ai Li‐Mei Zhang Shi‐Qing Xie Shu‐Hui Zi Sheng‐Chao Yang Yong Shen 《Helvetica chimica acta》2013,96(11):2155-2159
A further study of the alkaloid constituents of Aconitum forrestii led to the isolation of three new C19‐diterpenoid alkaloids, named 14‐acetoxy‐8‐O‐methylsachaconitine ( 1 ), 14‐acetoxyscaconine ( 2 ), and 8‐O‐ethylcammaconine ( 3 ). Their structures were determined by UV, IR, and MS, 1D‐ and 2D‐NMR analyses. 相似文献
85.
Abstract Cefpirome was synthesized in 37.7% overall yield from 3-chloromethyl-7-phenylacetylamino cephalosporanic acid p-methoxybenzyl ester (GCLE) by sequential substitution of C-3 chloride with iodide and 2,3-cyclopentenopyridine, followed by a one-pot procedure including deprotection of carboxyl group, hydrolysis of 7-phenylacetamido, and reaction with 2-mercaptobenzothiazolyl-(Z)-2-(2-aminothiazol-4-yl)-2-methoxyiminoacetate (MAEM). The reaction conditions were as follows: obtained from GCLE at low temperature (?5 to 0 °C) and absence of light, 3-iodomethyl-7-phenylacetylamino cephalosporanic acid p-methoxybenzyl ester (GILE) without purification was reacted directly with 2,3-cyclopentenopyridine, in which the molar ratio of GCLE, NaI, and 2,3-cyclopentenopyridine was 1:2:4, and the molar ratio of the resulting compound p-methoxybenzyl 7-phenylacetylamido-3-(2,3-cyclopenteno-1-pyridinio)methyl-3-cephem-4-carboxylate iodide and MAEM was 1:1.1. The structure of the intermediate and the target compound obtained were determined by nuclear magnetic resonance spectra and mass spectroscopy. 相似文献
86.
Zheng Wang Shuai Luo Dr. Shoude Zhang Wu‐Lin Yang Yang‐Zi Liu Prof. Dr. Honglin Li Prof. Dr. Xiaoyan Luo Prof. Dr. Wei‐Ping Deng 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(21):6739-6745
The first catalytic enantioselective 1,3‐dipolar cycloaddition of azomethine ylides to α‐aminoacrylate catalyzed by a AgOAc/ferrocenyl oxazolinylphosphine (FOXAP) system was developed, which exhibits excellent exo‐ and enantioselectivity (92–99 % ee). This process provides efficient access to useful 4‐aminopyrrolidine‐2,4‐dicarboxylic acid (APDC)‐like compounds containing a unique quaternary α‐amino acid unit. 相似文献
87.
Qiu‐Yan Chen Xian Cheng Tao Wang Zi‐Hao Yu Chong Zhang Shu‐Kun Lin Hao‐Hong Li Zhi‐Rong Chen 《无机化学与普通化学杂志》2014,640(2):439-443
A new low‐dimensional benzyl viologen/iodoargentate hybrid, [(BV)2(Ag5I9)]n ( 1 ) (BV2+ = benzyl viologen) was prepared. In 1 , (Ag6I9)n2– chain exhibits a new type of one‐dimensional chain constructed from vertex‐sharing of Ag5I10 units, and its two‐dimensional layer structure was constructed from C–H ··· I hydrogen bonds. Strong luminescence at 404 nm can be detected in 1 . DFT calculation suggests that 1 displays a reduced bandgap, which is led by a more dispersed LUMO band of BV2+ compared with MV2+ in [MV(Ag2I4)]n. 相似文献
88.
Sheng‐Run Zheng Xi‐Ling Wen Zi‐Meng Liu Tao Xie Jing‐Bo Tan Jun Fan Shuang‐Shuang Hou Wei‐Guang Zhang 《无机化学与普通化学杂志》2014,640(10):2057-2061
Two coordination polymers (CPs), namely, [Cu(Hptz)2(Hhba)2]n ( 1 ) [Hptz = 5‐(4‐pyridyl)‐1H‐tetrazole, H2hba = 2‐hydroxybenzoic acid] and [Zn3(ptz)2(hpa)2]n ( 2 ) (H2hpa = 2‐hydroxy‐2‐phenylacetic acid), were synthesized by solvothermal reactions. Both complexes were characterized by elemental analysis, infrared spectroscopy, powder X‐ray diffraction, thermogravimetric analysis, and single‐crystal X‐ray diffraction analysis. Compound 1 exhibits a 2D (4,4) network, where each layer connects to four adjacent layers to construct a 3D supramolecular framework. Compound 2 has a 3D framework structure composed of 1D SUBs, which are formed by both carboxyl and tetrazole groups. The complexes represent two rare examples of CPs constructed from Hptz and organic carboxyl acid ligands. Complex 2 exhibits intense, red‐shifted emissions in the visible region at room temperature. 相似文献
89.
An efficient tandem route to obtain tetrasubstituted NH pyrroles in a one-pot manner has been developed, staring from simple nitriles, ethyl bromoacetates, and zinc. This reaction involves oxidative dimerization of the zinc bromide complex of β-enaminoesters using cerium ammonium nitrate (CAN) as an oxidant, affording 2,3,4,5-tetrasubstituted pyrroles in yields up to 91%. 相似文献
90.
Qi Cong Ding Zi Tu Jianglin Wang Yuxing Wang Yinjie 《Journal of Thermal Analysis and Calorimetry》2021,144(6):2269-2284
Journal of Thermal Analysis and Calorimetry - As high heat dissipation has increasingly become the primary factor restricting the capability of electronic elements, and the high temperature of the... 相似文献