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991.
Cong‐Mei Cao Yi‐Bing Wu Rui‐Xia Guo Mei Dong Françoise Sauriol Chang‐Hong Huo Qing‐Wen Shi Teiko Yamada Hiromasa Kiyota Yu‐Cheng Gu Bin Cong 《Helvetica chimica acta》2013,96(3):375-378
Torreyanoxane, a novel 3,4‐secoglutinane triterpenoid, was isolated from the pulp of Torreya nucifera. The structure was determined on the basis of spectroscopic methods. 相似文献
992.
Seung Young Lee Kyeong Wan Woo Chung Sub Kim Dong Ung Lee Kang Ro Lee 《Helvetica chimica acta》2013,96(2):320-325
Three new furofuran lignans, (+)‐4,4′‐O‐diangeloylpinoresinol ( 1 ), (+)‐4,4′‐O‐diangeloylmedioresinol ( 2 ), and (+)‐4,4′‐O‐diangeloylsyringaresinol ( 3 ), together with the known compound (+)‐syringaresinol, were isolated from the MeOH extract of Rudbeckia laciniata. The structure elucidation of these compounds were based on 1D‐ and 2D‐NMR, and HR‐ESI‐MS data. The additional structural evidence was obtained from alkaline hydrolysis of the compounds. 相似文献
993.
The synthesis of 1‐arylsulfonyl‐4‐(1′‐N‐hepta‐O‐acetyl‐β‐lactosyl)thiosemicarbazides by reaction of hepta‐O‐acetyl‐α‐D‐lactosyl isothiocyanate with substituted phenylsulfonyl hydrazines has been shown to occur in less than 1 min under microwave activation and 8 min under ultrasound irradiation at room temperature. It is noteworthy that when ultrasound and microwaves (MW) were utilized, a cleaner reaction accompanied with higher yields was observed. 相似文献
994.
Cope rearrangement is one of the pericyclic reactions in many organic rearrangements. It has high stereoselectivity and has been widely used in organic synthesis chemistry. Herein, the discovery, mechanism, and application of Cope rearrangement were analyzed and discussed. 相似文献
995.
Treatment of N-tosyl-1-aryl-1,2,3,4-tetrahydro-isoquinolines or N-tosyl-1-aryl-1,2,3,4-tetrahydro-β-carbolines with a strong base such as NaOH or KOH at 70 °C in dimethylsulfoxide (DMSO) produced 1-aryl-3,4-dihydroisoquinolines or 1-aryl-3,4-dihydro-β-carbolines in good yields via mild and regiospecific β-eliminations. A dramatic solvent effect was observed, DMSO was crucial for the reactions. The temperature is also crucial for the reactions and should be kept between 60 and 80 °C. 相似文献
996.
1-Alkynylphosphonates 3 are prepared in a one-pot procedure from diethyl phosphorochloridates 2 and alkynyllithiums 1, which are readily generated by the reaction of 1-alkynes with n-BuLi. 相似文献
997.
A practical copper-catalyzed alkylarylation of activated alkenes with azobisisobutyronitrile (AIBN) and beyond has been developed, in which incorporation of 3o nitrile moiety into an oxindole scaffold proceeded smoothly through cascade radical addition/C(sp2)-H cyclization. The use of readily available AIBN as radical source and inexpensive CuI as catalyst, as well as broad substrate scope and the simplicity of operation and handling, make this protocol a highly attractive approach to oxindoles bearing 3o nitrile moiety. 相似文献
998.
999.
Qiong Wu Hui Feng Dong‐Dong Guo Mian‐Shuai Yi Xing‐Han Wang Bo Jiang Shu‐Jiang Tu 《Journal of heterocyclic chemistry》2013,50(3):599-602
A green and highly efficient method for the synthesis of polyfunctionalized indoline‐spiro fused pyran derivatives has been established. This reaction was conducted by reacting readily available and inexpensive starting materials, such as isatins, cyclic‐1,3‐dicarbonyl compounds, and malononitrile in aqueous media without any catalysts under microwave irradiation. The present green synthesis shows fascinating properties such as the use of water as the reaction solution, concise one‐pot conditions, short reaction periods (8–14 min), and easy purifications. The synthesis could also set a good example to GAP (Group‐Assistant‐Purification) chemistry in which purification via chromatography can be avoided and the pure products can be easily acquired only by washing the crude products with 95% EtOH. 相似文献
1000.
Yeon‐Ju Lee Dong‐Geun Lee Hyun Soo Rho Vladimir B. Krasokhin Hee Jae Shin Jong Seok Lee Hyi‐Seung Lee 《Journal of heterocyclic chemistry》2013,50(6):1400-1404
Three new 5‐hydroxyindole alkaloids ( 1 , 2 , 3 ) along with seven known analogs ( 4 , 5 , 6 , 7 , 8 , 9 , 10 ) were isolated from a Dokdo marine sponge Scalarispongia sp. The elucidation of the structures of the new compounds by spectroscopic analyses indicated that these compounds were an indole glyoxylate ( 1 ), a mono‐indole analog of hyrtinadine A ( 2 ), and a symmetrical bis‐indole with pyridine linker ( 3 ). The comparison of IC50 values for obtained compounds against a human leukemia cell line revealed that the bis‐indole structure is a requirement for cytotoxicity. 相似文献