A simple synthesis of novel and known calix[4]resorcinarenes derivatives has been achieved by the condensation of resorcinol and different aromatic aldehydes in the presence of catalytic amounts of Fe_3O_4 nanoparticl...A simple synthesis of novel and known calix[4]resorcinarenes derivatives has been achieved by the condensation of resorcinol and different aromatic aldehydes in the presence of catalytic amounts of Fe_3O_4 nanoparticles under solvent-free conditions.The experimental conditions have been thoroughly optimized and established,allowing significant rate enhancements and good to excellent yields.The reactions can be run safely without using any toxic organic solvents under mild reaction conditions.The Fe_3O_4 nanoparticles were characterized by powdered X-ray diffraction(XRD),transmission electron microscopy(TEM) and FT-IR spectroscopy.展开更多
An efficient procedure is reported for the synthesis of 3,3,6,6-tetramethyl-9-aryl-1,8-dioxooctahydroxanthenes using a one-pot condensation of arylaldehydes and 5,5-dimethyl-l,3-cyclohexandione in the presence of DABC...An efficient procedure is reported for the synthesis of 3,3,6,6-tetramethyl-9-aryl-1,8-dioxooctahydroxanthenes using a one-pot condensation of arylaldehydes and 5,5-dimethyl-l,3-cyclohexandione in the presence of DABCO-bromine (TDB) as an acid catalyst. To the best of our knowledge this is the first time that DABCO-bromine is used as an acid catalyst in aqueous media for this type of reaction. This method provides several advantages such as use of water as solvent, easy and clean synthesis, simple work up and versatility.展开更多
A series of new optically active [2-(1-hydroxyalkyl)pyrrolidino]methylferrocenes were conveniently prepared from commercially available L-proline and ferrocenecarboxylic acid. The crystal structure of key intermedia...A series of new optically active [2-(1-hydroxyalkyl)pyrrolidino]methylferrocenes were conveniently prepared from commercially available L-proline and ferrocenecarboxylic acid. The crystal structure of key intermediate was obtained. They were then applied to catalyze enantioselective addition of diethylzinc to arylaldehydes with enantioselectivity up to 99%. The effects of the ligand structures on the enantioselectivity were also studied.展开更多
In the condensation of arylaldehydes with arylethylidenemalononitriles, it was found that, besides the normal product dienes a, the ring-closure product quinoline derivatives b can be also obtained in 26%—50% yields...In the condensation of arylaldehydes with arylethylidenemalononitriles, it was found that, besides the normal product dienes a, the ring-closure product quinoline derivatives b can be also obtained in 26%—50% yields. The substituent effects were also examined and a possible reaction mechanism was proposed for the formation of b. The X-ray crystal structure of 1b confirms the structure of the ring-closure product.展开更多
以NCS为氯代试剂,在PPh3存在下,将芳香醛非常简便地转化为偕二氯代化合物,反应产率最高达到99%,该方法避免使用有毒的氯气作为氯代试剂,操作简单,反应条件温和,可在0℃下顺利进行.反应产物2f,2h,2i,2l,2m未见报道,其结构经1 H NMR,13 CN...以NCS为氯代试剂,在PPh3存在下,将芳香醛非常简便地转化为偕二氯代化合物,反应产率最高达到99%,该方法避免使用有毒的氯气作为氯代试剂,操作简单,反应条件温和,可在0℃下顺利进行.反应产物2f,2h,2i,2l,2m未见报道,其结构经1 H NMR,13 CNMR,IR和HRMS表征.展开更多
An efficient method for the synthesis of functionalized chroman-4-ones induced by visible light via the radical cyclization reaction of sulfinic acids and o-(allyloxy)arylaldehydes at room temperature was described.Th...An efficient method for the synthesis of functionalized chroman-4-ones induced by visible light via the radical cyclization reaction of sulfinic acids and o-(allyloxy)arylaldehydes at room temperature was described.The corresponding products were isolated with moderate to good yields.Radical mechanism was proposed fo r this trans formation.Anti-microbial activity of some desired compounds we re screened.展开更多
文摘A simple synthesis of novel and known calix[4]resorcinarenes derivatives has been achieved by the condensation of resorcinol and different aromatic aldehydes in the presence of catalytic amounts of Fe_3O_4 nanoparticles under solvent-free conditions.The experimental conditions have been thoroughly optimized and established,allowing significant rate enhancements and good to excellent yields.The reactions can be run safely without using any toxic organic solvents under mild reaction conditions.The Fe_3O_4 nanoparticles were characterized by powdered X-ray diffraction(XRD),transmission electron microscopy(TEM) and FT-IR spectroscopy.
文摘An efficient procedure is reported for the synthesis of 3,3,6,6-tetramethyl-9-aryl-1,8-dioxooctahydroxanthenes using a one-pot condensation of arylaldehydes and 5,5-dimethyl-l,3-cyclohexandione in the presence of DABCO-bromine (TDB) as an acid catalyst. To the best of our knowledge this is the first time that DABCO-bromine is used as an acid catalyst in aqueous media for this type of reaction. This method provides several advantages such as use of water as solvent, easy and clean synthesis, simple work up and versatility.
基金Project supported by the National Natural Science Foundation of China (No. 20172047) and the Education Commission of Henan Province.
文摘A series of new optically active [2-(1-hydroxyalkyl)pyrrolidino]methylferrocenes were conveniently prepared from commercially available L-proline and ferrocenecarboxylic acid. The crystal structure of key intermediate was obtained. They were then applied to catalyze enantioselective addition of diethylzinc to arylaldehydes with enantioselectivity up to 99%. The effects of the ligand structures on the enantioselectivity were also studied.
基金Project supported by the National Natural Science Foundation of China (No. 60171008) and the Ministry of Education China.
文摘In the condensation of arylaldehydes with arylethylidenemalononitriles, it was found that, besides the normal product dienes a, the ring-closure product quinoline derivatives b can be also obtained in 26%—50% yields. The substituent effects were also examined and a possible reaction mechanism was proposed for the formation of b. The X-ray crystal structure of 1b confirms the structure of the ring-closure product.
基金the National Natural Science Foundation of China(No.21772107)Shandong Province Key Research and Development Plan(No.2019GSF108017)。
文摘An efficient method for the synthesis of functionalized chroman-4-ones induced by visible light via the radical cyclization reaction of sulfinic acids and o-(allyloxy)arylaldehydes at room temperature was described.The corresponding products were isolated with moderate to good yields.Radical mechanism was proposed fo r this trans formation.Anti-microbial activity of some desired compounds we re screened.