合成了一种新化合物 {[Fe(PZDA)(H2O)2]·2H2O}n,并通过 X 射线衍射分析确定了其结构。该化合物由沿 a 轴的准梯形双链构成,其中 Fe(II) 离子通过羧基相连,羧基作为梯子的边缘,而吡嗪环则作为梯子的横档。变温磁 susceptibili 研究表明,该双链化合物存在自旋挫折现象。
A significant substituent effect on the regioselectivity in addition of alkynes to 3-substituted pyridines
作者:Shinji Yamada、Aya Toshimitsu、Yasuko Takahashi
DOI:10.1016/j.tet.2009.01.022
日期:2009.3
A substituent at the 3-position on a pyridine ring significantly affects the regioselectivity during the addition of alkynes to pyridinium salts. When the substituent is an electron-withdrawing group, 1,6-adducts are predominantly produced, whereas, 1,2-adducts become the major products when the substituent is an electron-donating group. The changes in the regioselectivity depending on the substituent