N,N,N(O,S),N(O,S)-四齿配体协同下钯促进的C-C交叉偶联反应

采用钯配合物催化C-C交叉偶联反应是形成C-C骨架的主要方法之一,该方法主要用于天然产物化学、药物化学、材料化学及超分子配体化学等诸多与化学合成相关的科学研究及应用领域。本文以廉价、易得的1,2-乙二胺、2-呋喃甲醛、2-噻吩甲醛及2-吡啶甲醛等为原料,合成了3种2-噻吩(呋喃、吡啶)甲醛亚胺类N,N,N(O,S),N(O,S)-四齿配体,并通过核磁共振谱(¹H NMR及¹³C NMR)及高分辨飞行时间质谱(HRMS)对所得产物的组成及结构进行了表征。在相对温和的反应条件下,将其应用到了钯催化的C-C交叉偶联反应中。发展了一种温和、高效的钯催化系统Pd(OAc)₂/N,N-亚乙基二(2-噻吩甲醛)亚胺(2b)/K₃PO₄/DMSO。并将该催化系统用于催化苯硼酸与溴代芳烃的C-C交叉偶联反应,获得了较高分离收率的偶联产物,最高可达94%。

Identification of Ginseng Root Rust -rot Pathogen Cylindrocarpon didymium and Its Biotransformation of Ginsenosides

Several Cylindrocarpon strains were obtained from rust rot disease -suspected roots of ginseg grown in Huanren areas of Liaoning province. They were confirned to be of pathogenicity to ginseng roots according to Koch ＇s postulation. The pathogenic strains SR79, SR86, SR88, SR90,SR91, SR94, SR95, SR96 were morphologically identified as Cylindrocarpon didymium. Among these pathogens strain SR79 was found to show the specificity to transform Rb1 and Rd ginsenosides into ginsenoside Rh2 by methods of TLC and HPLC. This strain was shown to possess commercial potential in ginsenoside transformation.