Selective Ring-Opening of Nonactivated Amino Aziridines by Thiols and Unusual Nucleophilic Substitution of a Dibenzylamino Group
作者:José M. Concellón、Pablo L. Bernad、José Ramón Suárez、Santiago García-Granda、M. Rosario Díaz
DOI:10.1021/jo0515069
日期:2005.11.1
The reaction of chiral 2-(1-aminoalkyl)aziridines 1 with different thiols, in the presence of BF3·Et2O, is reported. The obtained products were dependent on the structure of the starting amino aziridines 1. Thus, enantiopure (2S,3S)-2-(alkylthio)alkane-1,3-diamines 2 were obtained from aziridines with C-2 substituents with lower steric congestion and partially racemized (2S,3S)-2,3-bis(alkylthio)alkan-1-amines
报道了在BF 3 ·Et 2 O存在下手性2-(1-氨基烷基)氮丙啶1与不同硫醇的反应。所获得的产物取决于起始氨基氮丙啶1的结构。因此,对映体纯(2 S,3 S)-2-(烷硫基)链烷-1,3-二胺2从具有较低空间拥塞和部分消旋(2 S,3 S)-2的C-2取代基的氮丙啶获得, 3-双(烷硫基)烷-1-胺3(ee = 56-66%)来自具有较大C-2取代基的氮丙啶。在这两种情况下,未活化的氮丙啶环在C-2处的打开均保留了构型,并在C-2处进行了区域选择性和立体选择性。在3的合成中,2当量的硫醇与1反应,氮丙啶环在C-2处打开,随后第二个当量的硫醇异常取代二苄基氨基。通过单晶X射线分析确定化合物3的区域化学和相对构型。提出了一种机制来解释所获得的结果。