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901.
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
902.
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
903.
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
904.
905.
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
906.
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
907.
Wei Xu Ping Liu Chunhui Guo Chao Dong Xiuhua Zhang Shengfu Wang 《Mikrochimica acta》2013,180(11-12):1005-1011
We describe a molecularly imprinted electrochemical sensor for selective and sensitive determination of β2-agonists. It is making use of a combination of single-wall carbon nanotubes (SWNTs) with a molecularly imprinted sol–gel. The SWNTs were introduced in order to enhance electron transport and sensitivity. The imprinted sol–gel film with its specific binding sites acts as a selective recognition element and as a preconcentrator for β2-agonists. The morphology of the imprinted film was characterized by scanning electron microscopy. The optimized sensor displays high sensitivity and excellent selectivity for the β2-agonists as shown for their determination in human serum samples. Figure
A molecularly imprinted electrochemical sensor was constructed for selective and sensitive determination of β2-agonists. The optimized sensor displays high sensitivity and excellent selectivity for the β2-agonists as shown for their determination in human serum samples. 相似文献
908.
A selective and effective oxidation of alcohols into the corresponding aldehydes and ketones, respectively, with a new reagent, ferric(III) nitrate supported on kieselguhr, under heterogeneous conditions is reported. 相似文献
909.
Hong WooLee Tae WonKang Eung-Nam Kim Jaewook Shin Kyung HoiCha Dong OckCho 《合成通讯》2013,43(23):4345-4354
A method for preparing cephalosporin derivatives by reacting cephalosporin alkaline metal salts with organic halide in the presence of quarternary ammonium salts catalyst is disclosed. Δ3 to Δ2 isomerization, a side reaction commonly reported in preparation of cephalosporin derivatives, was successfully eliminated. The desired Δ3 was obtained as a sole product in the reaction. 相似文献
910.
Bi‐Dong Wu Zun‐Ning Zhou Yan‐Gang Bi Li Yang Jian‐Guo Zhang Tong‐Lai Zhang 《无机化学与普通化学杂志》2013,639(5):799-803
The intriguing multi‐ligand compound [Cu(IMI)4Cl]Cl ( 1 ) with the ligand imidazole (IMI) was synthesized and characterized by elemental analysis and FT‐IR spectroscopy. The crystal structure was determined by X‐ray single crystal diffraction and the crystallographic data showed that the compound belongs to the monoclinic P21/n space group [α = 8.847(2) Å, b = 13.210(3) Å, c = 13.870(3) Å, and β = 90.164(3)°]. Furthermore, the CuII ion is five‐coordinated by four nitrogen atoms from four imidazole ligands and a chlorine atom. The thermal decomposition mechanism was determined based on differential scanning calorimetry (DSC) and thermogravimetric (TG‐DTG) analysis. The non‐isothermal kinetics parameters were calculated by the Kissinger's method and Ozawa's method, respectively. The energy of combustion, enthalpy of formation, critical temperature of thermal explosion, entropy of activation (ΔS≠), enthalpy of activation (ΔH≠), and free energy of activation (ΔG≠) were measured and calculated. 相似文献