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171.
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
172.
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
173.
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
174.
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
175.
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
176.
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
177.
Fei Ma Gang L Wei Fen Zhou Qiu Juan Wang Yi Hua Zhang Qi Zheng Yao~* School of Pharmacy China Pharmaceutical University Nanjing China 《中国化学快报》2009,20(4):420-422
A series of novel 2,4-diamino-pteridines(9a-1)were synthesized and evaluated as inhibitors of inducible nitric oxide synthase (iNOS)in vitro.It was found that 9a,9d,9e,9h,9i and 91 showed potent inhibitory activities similar to that of methotrexate(MTX),while the activities of 9b,9c,9f,9g,9j and 9k ale stronger than MTX. 相似文献
178.
CHAOZi-Sheng* ZHOU Xiao- PingWAN Hui-Lin TSAI Khi-RuiDepartment of Clie-mudry Xiamen University Xiamen Fujian 《天然气化学杂志》1995,(2)
The oxidative coupling of methane(OCM)over ThO_2/CaF_2 catalystwas investigated.The catalyst was found to be active and selective for OCMreaction.At 1153 K,the C_2~ yield was 19.9% with 61.7% C_2~ selectivityand 32.1% CH_4 conversion.XRD results indicated that F~-(?)O~(2-)exchangehappened between ThO_2 and CaF_2 phases.XPS and Raman results suggestedthat the active oxygen species were generated and suitable for OCM reactionover the catalyst. 相似文献
179.
Chuan Jin Hou Xiao Mei Liang Jing Ping Wu Dao Quan Wang~* Key Lab of Pesticide Chemistry Application Technology Department of Applied Chemistry China Agricultural University Beijing China 《中国化学快报》2008,19(4):403-405
Two representative macrocyclic lactones with methoxysulfonyl side chain(5a and 5b)were synthesized employing Michael addition with acrolein and ring enlargement as the key steps,starting from potassium,α-oxocycloaikylsulfonates(1)in total yields of 45 and 57%,respectively. 相似文献
180.
Xue Yan SHI Hong Chao GUO Zhen QIAO Shi Cong HOU Min WANG* Key Laboratory of Pesticide Chemistry Application Technology College of Applied Chemistry China Agricultural University Beijing 《中国化学快报》2002,(10)
For high bioactivity of chiral pesticides, more and more chiral isomers are prepared by enantiomer resolution or asymmetric synthesis, and the sales of chiral pesticides continuously increase in recent years1. 1S-Allethrone I and 1S-propargyllone II are indispensable intermediates for synthesizing 1S-bioallethrin and prallethrin respectively, which are representatives of chiral pesticides. Usually, 1S enantiomers of allethrone and propargyllone are more active than their 1R enantiomers wh… 相似文献