Ring-Opening Reactions of 3-Aryl-1-benzylaziridine-2-carboxylates and Application to the Asymmetric Synthesis of an Amphetamine-Type Compound
作者:Tomoyuki Manaka、Shin-Ichiro Nagayama、Wannaporn Desadee、Naoki Yajima、Takuya Kumamoto、Toshiko Watanabe、Tsutomu Ishikawa、Masatoshi Kawahata、Kentaro Yamaguchi
DOI:10.1002/hlca.200790006
日期:2007.1
Nucleophilic ring-opening reactions of 3-aryl-1-benzylaziridine-2-carboxylates were examined by using O-nucleophiles and aromatic C-nucleophiles. The stereospecificity was found to depend on substrates and conditions used. Configuration inversion at C(3) was observed with O-nucleophiles as a major reaction path in the ring-opening reactions of aziridines carrying an electron-poor aromatic moiety, whereas
通过使用O-亲核试剂和芳香族C-亲核试剂检查了3-芳基-1-苄基氮丙啶-2-羧酸酯的亲核开环反应。发现立体特异性取决于所用的底物和条件。观察到在C(3)处的构型反转,其中O-亲核试剂是载有电子贫乏芳香族部分的氮丙啶的开环反应中的主要反应路径,而当富电子氮丙啶类化合物时通常会获得优先含有顺-非对映异构体的混合物进行了使用(表1-3)。在富电子氮丙啶与C-亲核试剂的反应中,观察到S N 2反应产生抗型产物(表4)。-通过催化氢化(+)的还原开环反应的反式- (2-小号,3 - [R)-3-(1,3-苯并二氧戊环-5-基)氮丙啶-2-羧酸甲酯(+) -反式- 3C,得到对应α -氨基酸衍生物,将其平稳地转变成(+) -叔-丁基[(1 - [R)-2-(1,3-苯并二氧戊环-5-基)-1-甲基乙基]氨基甲酸叔丁酯((+) - 14),并具有较高的光学纯度保留(方案6)。