Highly Stereoselective Intramolecular Hydroamination/Cyclization of Conjugated Aminodienes Catalyzed by Organolanthanides
作者:Sukwon Hong、Tobin J. Marks
DOI:10.1021/ja020226x
日期:2002.7.1
Efficient intramolecular hydroamination/cyclization of primary and secondary conjugated aminodienes can be effected by using organolanthanide precatalysts of the type Cp'2LnCH(TMS)2 (Cp' = eta5-Me5C5; Ln = La, Sm, Y; TMS = SiMe3) and CGCSmN(TMS)2 (CGC = Me2Si(eta5-Me4C5)(tBuN)). The transformation proceeds cleanly (>/= 90% conversion) at 25-60 degrees C with good rates and high regioselectivities,
通过使用 Cp'2LnCH(TMS)2(Cp' = eta5-Me5C5;Ln = La、Sm、Y;TMS = SiMe3)和 CGCsmN 类型的有机镧系元素预催化剂,可以实现伯和仲共轭氨基二烯的有效分子内加氢胺化/环化(TMS)2 (CGC = Me2Si(eta5-Me4C5)(tBuN))。转化在 25-60 摄氏度下顺利进行(>/= 90% 转化率),具有良好的速率和高区域选择性,并且电子效应导致显着的速率增强。该反应的一些特征与单取代的氨基烯烃加氢胺化/环化平行,包括速率定律([氨基二烯]中的零级),以及通过更大的镧系元素离子半径和/或更多开放的催化剂连接结构观察到的速率增强。2的合成中获得了良好到优异的非对映选择性,5-反式二取代吡咯烷(80% de)和2,6-顺式二取代哌啶(99% de)使用相应的α-甲基氨基二烯前体。2-(丙-1-烯基)哌啶与手性 C1-对称预催化剂 (