Trifluoromethyl-Substituted Phenylsilanes: The Regiochemical Course of Their Metalation Dictated by Buttressing Effects
作者:Manfred Schlosser、Christophe Heiss、Frédéric Leroux
DOI:10.1002/ejoc.200500729
日期:2006.2
Triethyl[(2-trifluoromethyl)phenyl]silane reacts with the superbasic LIC-KOR mixt. of butyllithium and potassium tert-butoxide exclusively at the 4-position ("meta-metalation") and not at all at the 3-position ("ortho-metalation"). Two further substrates which simultaneously contain two trifluoromethyl groups, triethyl[2,4- and 2,5-bis(trifluoromethyl)phenyl]silane, undergo deprotonation at the 5-
三乙基[(2-三氟甲基)苯基]硅烷与超碱性LIC-KOR混合物反应。丁基锂和叔丁醇钾仅在 4 位(“间位金属化”)而不在 3 位(“邻位金属化”)。同时含有两个三氟甲基的另外两种底物,三乙基[2,4-和2,5-双(三氟甲基)苯基]硅烷,分别在5-和4-位发生去质子化。因此,支撑效应阻止了金属化剂对任何三氟甲基的邻位的攻击,该基团在另一侧与三烷基取代基相邻。[在 SciFinder (R) 上]