Titanocene-Catalyzed Carbosilylation of Alkenes and Dienes Using Alkyl Halides and Chlorosilanes
作者:Shinsuke Nii、Jun Terao、Nobuaki Kambe
DOI:10.1021/jo000483p
日期:2000.8.1
A new method for regioselective carbosilylation of alkenes and dienes has been developed by the use of a titanocene catalyst. This reaction proceeds efficiently at 0 degrees C in THF in the presence of Grignard reagents by the combined use of alkyl halides (R'-X, X = Br or Cl) and chlorotrialkylsilanes (R3''Si-Cl) as the alkylating and silylating reagents, respectively. Terminal alkenes having aryl
通过使用钛茂催化剂,已经开发了一种用于烯烃和二烯的区域选择性碳硅烷化的新方法。该反应在格氏试剂的存在下于0摄氏度在THF中通过烷基卤化物(R'-X,X = Br或Cl)和氯三烷基硅烷(R3''Si-Cl)的烷基化和甲硅烷基化反应有效地进行试剂。具有芳基或甲硅烷基取代基的末端烯烃(YRC = CH2,Y = Ar或Me3Si,R = H或Me)以高收率得到加成产物YRC-(SiR''3)-CH2R',而1-辛烯和内部烯烃为迟缓。当使用2,3-二取代的1,3-丁二烯代替烯烃时,在相似的条件下,在1-和4-位引入烷基和甲硅烷基单元,从而以高收率得到烯丙基硅烷。本反应涉及(i)将烷基自由基加成至烯烃或二烯,和(ii)卤化苄基或烯丙基卤化镁与氯硅烷的亲电性。钛茂催化剂在这些活性物质,即烷基和苄基或烯丙基卤化镁的产生中起重要作用。