Catalytic cyclometallation of allylbenzenes by EtAlCl2 and Mg as new route to synthesis of dibenzyl butane lignans
作者:Lyudmila V. Parfenova、Tatyana V. Berestova、Pavel V. Kovyazin、Aydar R. Yakupov、Ekaterina S. Mesheryakova、Leonard M. Khalilov、Usein M. Dzhemilev
DOI:10.1016/j.jorganchem.2014.09.033
日期:2014.12
with EtAlCl2 (Et2AlCl) and Mg in the presence of Zr and Ti catalysts (Dzhemilev reaction) has been studied. The reaction run with high diastereoselectivity and gives cyclic organoaluminum compounds, which deuterolysis or hydrolysis gave 2R(S), 3R(S)-dibenzyl butanes with yield of 48–69%. The study of catalyst structure effect on the substrate conversion, reaction chemo- and stereoselectivity showed
在Zr和Ti催化剂存在下用EtAlCl 2(Et 2 AlCl)和Mg对烯丙基苯(Ar = Ph,4-MeO-Ph,3,4-(MeO)2 -Ph)进行环金属化反应(Dzhemilev反应)研究过。该反应以高非对映选择性进行,得到环状有机铝化合物,其经氘解或水解得到2 R(S),3 R(S)-二苄基丁烷,产率为48-69%。对催化剂结构对底物转化率,反应化学和立体选择性的影响的研究表明,在Cp 2 ZrCl 2的情况下获得了最佳结果在测试的复合物中。在反应中新薄荷烯基或新薄荷基四氢茚基锆催化剂的对映选择性不超过20%ee。的反式-在反应中形成的所述metallacycles的代用品的结构已经被证明由水解产物的X射线分析- 2 - [R (小号),3 - [R (小号) -二甲基-1,4-双[(4' )-甲氧基苯基)甲基]丁烷。所提出的方法可用于从容易获得的烯丙基苯一锅法非对映选择性地合成二苄基丁烷木脂素。