您当前的位置:首页 > TAG信息列表 > 有机合成

  • Efficient synthesis of glycerol carbonate from glycerol and urea with lanthanum oxide as a solid base catalyst
  • 更新时间:2014-04-10;信息类型:SCI论文
  • Lanthanum oxide catalyst prepared by precipitation method and calcined at 600 °C exhibited better catalytic activity in the catalytic synthesis of glycerol carbonate from glycerol and urea with TOF up to 1506 mmol/g·h. It was proposed that the lanthanum oxide catalyst with more strong basic sites (TdN400 °C) exhibited higher catalytic activity. Accordingly, the catalyst containing appropriate amount of La2O2CO3 phase exhibited higher catalytic activity. Moreover, the recycling experiments demonstrated that the catalytic activity can be essentially preserved during the recycling tests investigated.
  • 链接地址:http://www.ionike.com/download/article/2014-04-10/150.html
  • Quaternary Ammonium Ionic Liquids as Bi-functional Catalysts for One-step Synthesis of Dimethyl Carbonate from Ethylene Oxide, Carbon Dioxide and Methanol
  • 更新时间:2014-04-10;信息类型:SCI论文
  • One kind of novel ionic liquids (ILs) with a tertiary amino moiety and a quaternary ammonium group were synthesized and identified by FT-IR, 1H and 13C NMR. The elemental chemical state and basicity of ILs were determined by XPS and Hammett indicator method, respectively. Then the catalytic performance of these bifunctional catalysts was investigated in one-step synthesis of dimethyl carbonate (DMC) from ethylene oxide (EO), carbon dioxide and methanol. The best catalytic performance with 99% EO conversion and a maximum of 74% DMC selectivity was obtained using [N111,6N11]I as catalyst under optimized reaction conditions. And the catalyst could be reused for several times. Normally, stronger basicity could be obtained by altering the anions with different nucleophilicity in ILs and a better catalytic activity could be achieved correspondingly. A mechanism that both the ring opening of epoxide through nucleophilic attacks and the transesterification play an important role in the reaction was proposed based on experimental results.
  • 链接地址:http://www.ionike.com/download/article/2014-04-10/139.html
  • Palladium catalyzed N-alkylation of amines with alcohols
  • 更新时间:2014-04-10;信息类型:SCI论文
  • An iron oxide immobilized palladium catalyst was prepared for the N-alkylation of amines with alcohols under base and organic ligand free conditions. Applying the optimized reaction conditions, the coupling reactions of amines and alcohols with various structures could be realized with up to 99% isolated yields. The catalysts were studied by XRD, BET, and XPS and the mechanism was studied by DFT calculations.
  • 链接地址:http://www.ionike.com/download/article/2014-04-10/138.html
  • Organic Ligand-Free Alkylation of Amines, Carboxamides, Sulfonamides,and Ketones by Using Alcohols Catalyzed by Heterogeneous Ag/Mo Oxides
  • 更新时间:2014-04-10;信息类型:SCI论文
  • Complicated and expensive organic ligands are normally essential in fine chemical synthesis at preparative or industrial levels. The synthesis of fine chemicals by using heterogeneous catalyst systems without additive organic ligand is highly desirable but severely limited due to their poor generality and rigorous reaction conditions. Here, we show the results of carbon–nitrogen or carbon–carbonbond formation catalyzed by an Ag/Mo hybrid material with specific Ag6Mo10O33 crystal structure. 48 nitrogen-or oxygen-containing compounds, that is, amines, carboxamides, sulfonamides, and ketones, were successfully synthesized through a borrowing-hydrogen mechanism. Up to 99% isolated yields were obtained under relatively mild conditions without additive organic ligand. The catalytic process shows promise for the efficient and economic synthesis of amine, carboxamide, sulfonamide, and ketone derivatives because of the simplicity of the system and ease of operation.
  • 链接地址:http://www.ionike.com/download/article/2014-04-10/137.html
 108   首页 上一页 3 4 5 6 7 8 9 10 11 下一页 尾页