A novel and green method for the synthesis of dimethyl pyridine-3,5-dicarboxylate has been developed. It is PdCl2-catalyzed heterocyclotrimerization of methyl acrylate with urea in methanol/supercritical carbon dioxide. The target compound was obtained with a 75% isolated yield under the optimized con-ditions.
ZOU Bo,JIANG HuanFeng College of Chemistry,South China University of Technology,Guangzhou 510640,China
DNA photocleavage properties of halogenated mono-hydroxyl corrole 1-5 were investigated.It was found that these corroles were able to photocleavage supercoiled pBR 322 DNA(SC) into nicked-circular DNA(NC).The activity of these corroles follows an order of 4>3>2≈1>5.The photosensitized singlet oxygen(Φ_△) quantum yield by these corroles also follows that same order,showing the photocleavage activity is related to the heavy atom effect of halogen atoms on corroles.
The coupling reaction of carbon dioxide with epoxides was investigated using naturally occurring α-amino acids as the catalyst in supercritical carbon dioxide and it was found that L-histidine is the most active catalyst.In the presence of 0.8 mol% of L-histidine at 130°C under 8 MPa of CO2,the reaction of carbon dioxide with epoxides proceeded smoothly,affording corresponding cyclic carbonates in good to excellent yields.
QI ChaoRong & JIANG HuanFeng* School of Chemistry and Chemical Engineering,South China University of Technology,Guangzhou 510640,China
Polystyrene-supported hydroquinone (PS-HQ) is presented as an in situ polymeric cocatalyst to replace polystyrene- supported benzoquinone (PS-BQ) in the PdCl_2-catalyzed acetalization of methyl acrylate with methanol in supercritical carbon dioxide (scCO_2) under oxygen atmosphere.Due to deletion of H_2O_2 oxidation step,PS-HQ is more convenient and relatively inexpensive.
Zhao Yang WangHuan Feng JiangChao Rong QiYan Xia ShenShao Rong Yang
