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171.
Xue Mei NIU Sheng Hong LI Li Yan PENG Gao Xiong RAO Han Dong SUN* Laboratory of Phytochmistry Kunming Institute of Botany Academia Sinica Kunming Yunnan College of Traditional Chinese Medicine Kunming 《中国化学快报》2001,(3)
Limonia crenulata Roxb. (Rutaceae), a small tree widely distributed in dry warm regions of southeastern Asia, has been reported to have antiepileptic, purgative and sudorific effects and is used for colic trouble and cardialgia1. Various parts of this plant have been employed in indigenous medicine. Our investigation on its stems led to the isolation of one new alkaloid, crenulatine 1, together with three known ones, 4-methoxy-6- hydroxy-1-methyl-2-quinolone2, N-benzoyltyramine methyl ether2,… 相似文献
172.
Wei Hong SONG Xuan Zhen JIANG* Department of Chemistry Zhejiang University Hangzhou 《中国化学快报》2001,(3)
Dimethyl malonate (DMM) is an important organic synthesis intermediate. Traditional synthetic method by reaction of mono-chloroacetic acid with sodium cyanide1 is poisonous and complicated. Therefore, an interest in green synthesis routes of DMM has risen greatly. The several processes for preparing DMM by carbonylation of methyl chloroacetate catalyzed by Co2(CO)8 have been reported2~5. However, Co2(CO)8 is unstable and must be prepared under high pressure (12 Mpa). Moreover, the yield… 相似文献
173.
Yong WU* Mei GUAN Pei Jie LI Cheng XU Xiao Chun WU School of Pharmacy West China University of Medical Sciences Chengdu The First Hospital West China University of Medical Sciences Chengdu 《中国化学快报》2001,(1)
Since the last decade, there has been a growing interest in the development of analogues of 1(, 25- dihydroxyvitamin D3 1 with low calcemic effect but increased cell differentiating ability1. Among side chain and the A-ring modifications of 1, the 1(, 25- dihydroxy-22-oxo-vitamin D3 22 and 19-nor-1(, 25- dihydroxyvitamin D3 33 have shown much lower calcemic effect and stronger cell differentiating ability than 1. In this paper, we reported synthesis of 19-nor-1(, 25-dihydroxy-22-oxo-vitamin … 相似文献
174.
Cheng Lu ZHANG Ping Yan BIE Xuan Jia PENG Xin Fu PAN* Department of Chemistry National Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 《中国化学快报》2002,13(10)
Most diterpenoids exhibit significant bioactivities, such as antidermatophytic, antibact- erial, and antioxidant. Although a large number of aromatic tricyclic diterpenoids have been isolated, there are a few of them having ethyl substituent. The synthesis of this type diterpenoids has been seldom reported. In order to further study the relationship between the structure and bioactivities of the diterpenoid, we extended the diterpene synthesis1,2,3. It is desirable to report herein the syn… 相似文献
175.
Ya Ping WANG Liang Xi LI Qing Lian WANG Yu Lin LI* National Laboratory of Applied Organic Chemistry Institute of Organic Chemistry Lanzhou University Lanzhou 《中国化学快报》2002,13(10)
Isoliquiritin 1 was isolated from the roots of G. uralensis and also from other plants, and has been reported to exhibit antitumour, anti-HIV, curing hepatitis activities1, 2, use as anti-allergic drug4, and for sweetening3. It has been used for a strong inhibitor of hyaluronidase4. HOOHOOGluc561'2'3'4'5'6'1243βα1 OHHOOHHHHOHHOHGluc=2"3"4"6"1"5" The synthesis of isoliquiritin (4-glucopyranoxy-2,4-dihydroxy chalcone) has not been reported, because there is no suitable synth… 相似文献
176.
Construction of the Skeleton of Phthalascidin, Mechanism of the Formation of the Key Tricyclic Lactam Intermediate 总被引:1,自引:0,他引:1
Zhan Zhu LIU Ye WANG Shi Zhi CHEN* Institute of Materia Medica Chinese Academy of Medical Sciences& Peking Union Medical College Beijing 《中国化学快报》2002,13(8)
Phthalascidin is a structurally simplified version of Et-743, which is a potent anti-tumor marine natural product isolated from Ecteinascidia turbinata. Its antiproliferative activity is greater than that of the agents taxol, camptothecin, adriamycin, mitomycin C, cisplatin, bleomycin, and etoposide by 1-3 orders of magnitude. An elegant synthesis of Et-743 and phthalascidin has been reported by E. J. Corey and co-workers1,2. As part of our continuing program, we have also engaged in dev… 相似文献
177.
Zhen QIAO Xue Yan SHI Qing Hua BIAN Shi Cong HOU Min WANG* Shandong Pesticide Research Institute Jinan College of Sciences China Agricultural University Beijing 《中国化学快报》2004,15(9)
Bis(oxazoline) ligands1 have been successfully used in a variety of metal-catalyzed asymmetric reactions, such as cyclopropanation, allylic oxidation reactions, etc; Chiral ferrocene derivatives2 have also been proved as effective ligands in numerous asymmetric reactions, for example, chiral ferrocenylphosphines exhibited high enantioselectivity for the reduction of olefins, Heck reactions and Aldol reactions of aldehydes. These results stimulated us to study the behaviour the bis(oxazoline) … 相似文献
178.
Xing Xian ZHANG Wei Dong Z. LI* National Laboratory of Applied Organic Chemistry & Institute of Organic Chemistry Lanzhou University Lanzhou 《中国化学快报》2003,(8)
In our previous letter1, we have reported the unique catalytic reactivity of MgI2 etherate 1 in the chemoselective Mukaiyama-type aldol reactions of aryl or vinyl aldehyde and aldehyde acetals with silyl enolates. Aryl or alkyl a, b-unsaturated aldehydes (and their acetals) are particularly reactive in this catalytic addition reaction due to possibly the effective activation of the electron-rich carbonyl by highly oxyphilic Lewis acidic species, i.e. IMg+, in non-coordinative media (i.e. CH… 相似文献
179.
XU Long-Ya* WANG Qing-XiaLIANG Dong-Bai TIAN Zhi-JianYANG Li ZHAO Xiu-Shen WANG Kai-LiDalian Institute of Chemical Physics Academia Smica Dalian Ijiaaning 《天然气化学杂志》1995,(2)
High selectivity to light alkenes can be achieved from CO and CO_2hydrogenation over K-Fe-MnO/Si-2 catalyst.The alkene selectivity isinsensitive to reaction temperature for CO hydrogenation,while apparentlyincreases for CO_2 hydrogenation with raising reaction temperature.An increasein alkene selectivity is observed for both CO and CO_2 hydrogenation with GHSVrising,While a decrease with the elevation of reaction pressure for both CO/H_2and CO_2/H_2 reaction.A two-step mechanism is suggested forCO_2 hydrogenation to form hydrocarbons,by which the variations incontributions of CO and HC as products of CO_2/H_2 reaction with change ofreaction temperature,GHSV and pressure are explained.Moreover,thecatalyst is favorable for selective production of light olefins,which can alsoconcern the slightly secondary reactions of light olefins to some extent. 相似文献
180.
Yan LI Han Fan LIU* PCLCC Center for Molecular Science Institute of Chemistry Chinese Academy of Sciences Beijing 《中国化学快报》2001,(2)
Nanoscopic metal clusters, because of their substantial difference from metal atoms and bulk metals in size and structure, have attracted great interest especially in the field of catalysis1. It is well known that additives can markedly affect the properties of metal catalysts. The effect of metal ions has been well studied in the field of heterogeneous catalysis2. However, the study of metal complex effect is scarce. We have reported that the metal complex can considerably modulate both the a… 相似文献