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941.
Zhao‐Hui Yan Zhu‐Zhen Han Xian‐Qing Hu Qing‐Xin Liu Wei‐Dong Zhang Run‐Hui Liu Hui‐Liang Li 《Helvetica chimica acta》2013,96(1):85-92
Two new sesquiterpenes, 1 and 2 , as well as the five known compounds 3 – 7 , were isolated from the stems of Euonymus alatus. Compounds 2 – 7 have a β‐dihydroagarofuran skeleton. The structures of these compounds were elucidated mainly by spectroscopic methods (1D‐, 2D‐NMR, ESI‐MS, and HR‐ESI‐MS). We also report the X‐ray crystal structure of evonine ( 3 ) for the first time. 相似文献
942.
Yisheng Sun Zhao Zhao Qiangsheng Feng Qinqin Xu Longxian Lü Ji‐Kai Liu Ling Zhang Bin Wu Yong‐Quan Li 《Helvetica chimica acta》2013,96(1):76-84
Investigation of the cultured mycelia of Cordyceps ophioglossoides resulted in the isolation and characterization of three new unusual spiro[4.5]decane sesquiterpenes, cordycepol A ( 1 ), cordycepol B ( 2 ), and cordycepol C ( 3 ), and a new fumagillol analogue, cordycol ( 4 ). Their structures were established by spectroscopic means. The cytotoxic activities were also evaluated, compounds 3 and 4 showing their IC50 values in the range of 12–33 μg/ml against HeLa and HepG2 (Table 3). In addition, 3 and 4 were not obviously harmful towards normal liver cell lines LO2, showing IC50 values above 80 μg/ml. 相似文献
943.
The BiCl3‐catalyzed reaction of pyrroles with electron‐deficient olefins generated the corresponding Michael adducts in high yields. 相似文献
944.
The Knoevenagel condensation of Meldrum's acid with aromatic aldehydes proceeded efficiently in a reusable ionic liquid, ethylammonium nitrate, at room temperature in the absence of any catalyst with high yields. 相似文献
945.
A practical and efficient liquid‐phase synthesis of 3,4,5‐trisubstituted isoxazoles using poly(ethylene glycol) as supported is described. Soluble‐polymer‐supported nitrile oxide generated in situ reacted with chalcones to afford polymer‐supported isoxazolines, which were cleaved by sodium methoxide to generate 3,4,5‐trisubstituted isoxazoles instead of 3,4,5‐trisubstituted isoxazolines. This sequential process provided a novel method to synthesize 3,4,5‐trisubstituted isoxazoles. 相似文献
946.
Two types of β‐enaminoketone derivatives of 3‐(2‐oxo‐2‐arylethylidene)‐3,4‐dihydro‐1H‐quinoxalin‐2‐ones and 3‐(2‐oxo‐2‐arylethylidene)‐3,4‐dihydro‐benzo[1,4]oxazin‐2‐ ones were effectively and conveniently prepared in good to excellent yields under solvent‐free conditions via the catalysis of sulfamic acid in the corresponding condensations of o‐phenylenediamine and o‐aminophenol with ethyl 2,4‐dioxo‐4‐arylbutyrate respectively. The compounds were confirmed by IR, 1H NMR, and 13C NMR, and a representative was further determined by X‐ray crystallography. 相似文献
947.
α,β-Unsaturated aldimines were specifically oxidized to amides with Oxone in the presence of AlCl3 as a Lewis acid in CH2Cl2. No migration of aryl group occurred in the rearrangement reaction. 相似文献
948.
The reaction of diaryliodonium salts with β-substituted-α,β-enones in the presence of a palladium catalyst affords Hβ-substituted products with excellent yields. 相似文献
949.
A convenient one-pot synthesis of benzo[f]pyrimido[4,5-b]quinoline derivatives is described via three-component reaction of benzaldehydes, naphthalen-2-amine, and barbituric acid at room temperature in aqueous media catalyzed by iodine. Compared with other methods, this three-component reaction used a green solvent, gave good yields, and was operationally simple. 相似文献
950.
Triazolo‐fused 2′,3′‐cyclic nucleoside analogs were synthesized by an intramolecular 1,3‐dipolar cycloaddition of nucleoside‐derived azido alkynes in a regio‐ and stereospecific manner. The uracil base in these target compounds was successfully transformed to the corresponding cytosine. The synthesized compounds were examined in a MAGI assay for their anti‐HIV activities, and in a H9 T lymphocytes assay for their cell toxicities. 相似文献