Synthesis and catalytic activity of ruthenium complexes modified with chiral racemic per- and polyfluorooxaalkanoates
作者:Pavlína Lipovská、Lucie Rathouská、Ondřej Šimůnek、Jan Hošek、Viola Kolaříková、Markéta Rybáčková、Josef Cvačka、Martin Svoboda、Jaroslav Kvíčala
DOI:10.1016/j.jfluchem.2016.09.005
日期:2016.11
Silver salts of racemic 2H-perfluoro(3-oxahexanoic) (3a), perfluoro(2-methyl-3-oxahexanoic) (3b) and 2,3,3,3-tetrafluoro-2-methoxypropanoic acid (3c) gave with Hoveyda-Grubbs 2nd generation catalyst 4 or its bis(polyfluoroalkylated) analogue 5 the corresponding bis(polyfluoroacylated) ruthenium complexes 1a–1c or 2a, 2b as mixtures of three diastereoisomers. Their catalytic activity in model ring-closing
外消旋的2 H-全氟(3-氧杂己酸)(3a),全氟(2-甲基-3-氧杂己酸)(3b)和2,3,3,3-四氟-2-甲氧基丙酸(3c)的银盐分别为Hoveyda-Grubbs第二代催化剂4或其双(多氟烷基化)类似物5对应的双(多氟酰化)钌络合物1a - 1c或2a,2b是三种非对映异构体的混合物。它们在模型闭环复分解(RCM)反应中的催化活性以1b–2b > 1a–2a > 1c的顺序降低由于络合物1a,1c和2a中催化中心周围的位阻增加,以及由于酸3c的酸性较低,导致络合物1c的亲电性较低。因此,配合物1b和2b在形成双取代(RCM2)或三取代(RCM3)双键的双不饱和丙二酸酯的RCM中显示出高活性,甚至在形成四取代键(RCM4)方面具有显着活性,而配合物1a,1c为在RCM2中有效,但在RCM3中无效。而且,配合物1c催化的RCM2的产率相当低。