使用衍生自稳定的螺硼酸酯,通过硼烷介导的单一异构体 ( E )- 和 ( Z ) -O-苄基肟醚的还原,合成了高对映体纯的 (1-芳基)-和 (1-萘基)-1-乙胺( S )-二苯基缬氨醇和乙二醇作为手性催化剂。伯 ( R )-芳基乙胺是通过使用 15% 的催化剂将纯 ( Z )-乙酮肟醚还原至 99% ee来制备的。描述了使用对映纯(1-萘-1-基)乙胺作为手性前体合成新的和已知的拟钙剂类似物的两种方便且容易的方法。
使用衍生自稳定的螺硼酸酯,通过硼烷介导的单一异构体 ( E )- 和 ( Z ) -O-苄基肟醚的还原,合成了高对映体纯的 (1-芳基)-和 (1-萘基)-1-乙胺( S )-二苯基缬氨醇和乙二醇作为手性催化剂。伯 ( R )-芳基乙胺是通过使用 15% 的催化剂将纯 ( Z )-乙酮肟醚还原至 99% ee来制备的。描述了使用对映纯(1-萘-1-基)乙胺作为手性前体合成新的和已知的拟钙剂类似物的两种方便且容易的方法。
efficient, reusable and stable binaphthyl stabilized Pd‐nanoparticles (Pd‐BNP) catalyzed the direct ortho‐C−H hydroxylation of acetophenone oxime ethers under neutral and phosphineligand‐free condition has been developed. A readily available, economic, safe and greener oxidant oxone has been used in this direct ortho‐hydroxylation. The scope of the reaction has been studied with various acetophenone oxime
Enantioselective reduction of ketoxime ethers with borane–oxazaborolidines and synthesis of the key intermediate leading to (S)-rivastigmine
作者:Marcin M. Pakulski、Sanjit K. Mahato、Mariusz J. Bosiak、Marek P. Krzeminski、Marek Zaidlewicz
DOI:10.1016/j.tetasy.2012.05.008
日期:2012.5
The reduction of representative alkyl aryl (E)-ketoxime O-benzyl ethers with borane catalyzed by terpene oxazaborolidines, derived from (1R)-nopinone and (1R)-camphor, gave the corresponding amines with 82-99% ee. Oxazaborolidines derived from (1S)-2-carene and (1S)-3-carene were less selective. (S)-1-(3-Methoxyphenyl)ethanamine (94% ee) the key intermediate in the synthesis of (S)-rivastigmine, was obtained by the reduction of (E)-1-(3-methoxyphenyl)ethanone O-benzyl oxime with borane/oxazaborolidine generated from (S)-valinol. (C) 2012 Elsevier Ltd. All rights reserved.