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231.
Gideon Fraenkel Albert Chow Yulan Liang Jinhua Song Judith Gallucci 《Helvetica chimica acta》2012,95(11):2063-2071
In a one‐pot process without isolation of intermediates, (but‐3‐en‐1‐yl)pyridine ( 13 ) is treated sequentially with dicyclohexylborane, trimethylaluminium, and ethyl carbonochloridate yielding ethyl 1,4‐dihydro‐4,4‐(tetramethylene)pyridine‐1‐carboxylate (=ethyl 8‐azaspiro[4.5]deca‐6,9‐diene‐8‐carboxylate; 2 ) in 46% yield based on starting alkenylpyridine 13 (Scheme 5). 相似文献
232.
Qiaoxia Liu Binbin Zhou Xinliang Wang Yanxiong Ke Yu Jin Lihui Yin Xinmiao Liang 《Journal of separation science》2012,35(23):3317-3325
A search library about benzylisoquinoline alkaloids was established based on preparation of alkaloid fractions from Rhizoma coptidis, Cortex phellodendri, and Rhizoma corydalis. In this work, two alkaloid fractions from each herbal medicine were first prepared based on selective separation on the “click” binaphthyl column. And then these alkaloid fractions were analyzed on C18 column by liquid chromatography coupled with tandem mass spectrometry. Many structure‐related compounds were included in these alkaloids fractions, which led to easy separation and good MS response in further work. Therefore, a search library of 52 benzylisoquinoline alkaloids was established, which included eight aporphine, 19 tetrahydroprotoberberine, two protopine, two benzyltetrahydroisoquinoline, and 21 protoberberine alkaloids. The information of the search library contained compound names, structures, retention times, accurate masses, fragmentation pathways of benzylisoquionline alkaloids, and their sources from three herbal medicines. Using such a library, the alkaloids, especially those trace and unknown components in some herbal medicine could be accurately and quickly identified. In addition, the distribution of benzylisoquinoline alkaloids in the herbal medicines could be also summarized by searching the source samples in the library. 相似文献
233.
Jin‐Yun Wang Chen‐Sheng Lin Min‐Yi Zhang Guo‐Liang Chai Wen‐Dan Cheng 《International journal of quantum chemistry》2012,112(3):759-769
Geometrical structures of the investigated endohedral metallofullerenes Sc3N@C2n (2n = 68, 70, 78, and 80) were optimized at the B3LYP/6‐31G* level. The analyses of electronic structures display that the contribution of fullerene cage to the lowest unoccupied molecular orbital decreases as the cage size increases. Based on the optimized structures, the time‐dependent density functional theory combined with the sum‐over‐states method was used to investigate their nonlinear optical properties. Calculated third‐order polarizabilities γ and two‐photon absorption (TPA) cross‐section δ do not present the monotone variation with the size of fullerene cage, with largest γ of 0.48 × 10?34 esu for Sc3N@C78 in static state, and largest δ of 12.374 GM for Sc3N@C70 in the wavelength of 902.5 nm. However, the obtained TPA resonant peaks shift red with the size of fullerene cage. By analyzing the electronic origin of the third‐order optical properties, it is found that the charge transfers from the fullerene cage to the encapsulated Sc3N cluster make important contributions to the studied properties. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011 相似文献
234.
Shuo Tong Xu Yang De-Xian Wang Liang Zhao Jieping Zhu Mei-Xiang Wang 《Tetrahedron》2012,68(32):6492-6497
The reactivity of stable tertiary enamides in nucleophilic addition reaction with various in-situ generated imines was explored. Under very mild conditions, formyl-bearing tertiary enamides reacted with both aromatic and aliphatic amines to form imine intermediates. In the absence or presence of p-toluenesulfonic acid as a catalyst, intramolecular nucleophilic addition of enamide to imine functionality proceeded effectively to produce diverse 4-amino-1,2,3,4-tetrahydropyridine derivatives in good to excellent yields. 相似文献
235.
236.
Ji Jinfeng Song Guangliang Cai Xiao Hu Jinyang Feng Liang Zhu Hongjun 《Research on Chemical Intermediates》2016,42(6):5597-5605
Research on Chemical Intermediates - A spirooxazine derivative 1,3-dihydro-1,3,3-trimethyl-spiro[2-H-indole-2-2′-[2H-1,4] oxazino [2,3-f] [1, 10] phenanthroline] (compound 1) was explored as... 相似文献
237.
Yong Li Yingzheng Shu Muwen Liang Dr. Xilei Xie Dr. Xiaoyun Jiao Prof. Xu Wang Prof. Bo Tang 《Angewandte Chemie (International ed. in English)》2018,57(38):12415-12419
Carbon monoxide (CO) is proposed as an active pharmaceutical agent with promising pharmaceutical prospects, as it has been involved in multifaceted modulation of diverse physiological and pathological processes. However, questions remain for therapeutic application of inhaled CO attributed to the inherent great affinity between CO and hemoglobin. Therefore, a robust platform with the function of CO transport and controllable release, depending on the local status of an organism, is of prominent significance for effectively avoiding the side effects of CO inhalation and optimizing the biological regulation function of CO. Utilizing the oxidative stress biomarker H2O2 as a trigger and combining with photo‐control, a two‐photon H2O2‐activated CO photoreleaser, FB, featuring highly sensitive and specific H2O2 sensing and photocontrollable CO release, was developed and the vasodilation effect of CO against angiotensin II was demonstrated. 相似文献
238.
Mujuan Chen Jidong Liang Zhijian Zeng Xin Lin Shilong Zhang Lasheng Jiang 《Tetrahedron letters》2017,58(35):3437-3440
A new type of self-complexed bis-crown ether containing two bis(p-phenylene)-34-crown-10 (BPP34C10) ether rings and two secondary ammoniums has been synthesized and characterized. The formation of these bis-self-complexes has been identified by NMR spectroscopy, mass spectrometry and X-ray analysis. The acid/base controlled movement of these bis–crown ethers can mimic a flapping butterfly. 相似文献
239.
Jia‐Xiang Yang Yu‐Peng Tian Qing‐Liang Liu Yong‐Shu Xie Hoong‐Kun Fun Suchada Chantrapromma Ibrahim Abdul Razak 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):m43-m44
In the title compound, [Fe(C5H5)(C16H12N3OS)], the 8‐aminoquinoline and acylthiourea moieties are almost planar. There are two perpendicular arrangements of the molecules in the crystal with slightly different conformations. The two cyclopentadienyl rings in each molecule are parallel and eclipsed. 相似文献
240.