Ring-Opening Reactions of 3-Aryl-1-benzylaziridine-2-carboxylates and Application to the Asymmetric Synthesis of an Amphetamine-Type Compound

✍ Scribed by Tomoyuki Manaka; Shin-Ichiro Nagayama; Wannaporn Desadee; Naoki Yajima; Takuya Kumamoto; Toshiko Watanabe; Tsutomu Ishikawa; Masatoshi Kawahata; Kentaro Yamaguchi

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: German
• Weight: 218 KB
• Volume: 90
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.200790006

✦ Synopsis

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 mixtures containing preferentially the syn-diastereoisomer were generally obtained when electron-rich aziridines were used (Tables 123). In the reactions of electron-rich aziridines with C-nucleophiles, S N 2 reactions yielding anti-type products were observed (Table 4). Reductive ring-opening reaction by catalytic hydrogenation of (+)-trans-(2S,3R)-3-(1,3-benzodioxol-5-yl)aziridine-2-carboxylate (+)-trans-3c afforded the corresponding a-amino acid derivative, which was smoothly transformed into (+)-tert-butyl [(1R)-2-(1,3-benzodioxol-5-yl)-1-methylethyl]carbamate((+)-14) with high retention of optical purity (Scheme 6).