Chalcogenide-Lewis Acid Mediated Reactions of Electron-Deficient Alkynes with Aldehydes
作者:Sayaka Kinoshita、Hironori Kinoshita、Tatsunori Iwamura、Shin-ichi Watanabe、Tadashi Kataoka
DOI:10.1002/chem.200390169
日期:2003.4.4
Reactions of but-3-yn-2-one (2) with aldehydes 1 in the presence of a Lewis acid and dimethyl sulfide (3 a) predominantly gave (E)-alpha-(halomethylene)aldols 4-5 in high yields, while reactions of methyl propiolate (6 a) mainly afforded (Z)-3-halogeno-2-(hydroxymethyl)acrylates 7-8 in low to moderate yields. A reaction of dimethyl acetylenedicarboxylate (10) with 1 a in the presence of TiCl(4) and
But-3-yn-2-one(2)与醛1在路易斯酸和二甲基硫醚(3 a)存在下的反应主要以高收率得到(E)-α-(卤代亚甲基)醛醇4-5,而丙酸甲酯(6a)的反应主要以低到中等的产率提供(Z)-3-卤代-2-(羟甲基)丙烯酸酯7-8。乙炔二甲酸二甲酯(10)在TiCl(4)和1,1,3,3-四甲基硫脲(3 c)存在下与1 a反应生成马来酸酯(E)-11(40%)和丁烯内酯12(40%) )。在TiBr(4)和3a(0.2当量)存在下于-20℃下进行6a与1a的反应60小时后,3-(甲硫基)-2-(羟烷基)丙烯酸酯9a以8%的产率获得。为了阐明9a的形成机理进行了实验,