Effect of a Substituent on an Aromatic Group in Diastereomeric Resolution

✍ Scribed by Kazushi Kinbara; Koji Oishi; Yoshiko Harada; Kazuhiko Saigo

• Publisher: Elsevier Science
• Year: 2000
• Tongue: French
• Weight: 120 KB
• Volume: 56
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(00)00472-5

✦ Synopsis

AbstractÐThe diastereomeric resolution of p-substituted 1-arylethylamines by enantiopure (S)-3 H ,4 H -methylenedioxymandelic acid ((S)-2) was carried out in order to know how an electron-donating or -withdrawing group on the aromatic group of the racemic amines would affect the ef®ciency of resolution. As a result, it was found that 1-arylethylamines having an electron-withdrawing substituent could be ef®ciently resolved by (S)-2, while the amines having an electron-donating group could not. The crystal structures of the less-and more-soluble salts, and the molecular orbital calculations of the ammonium cations indicated that the p-substituted electron-withdrawing group enhanced the positive charge on the meta-hydrogen of the aromatic group of the ammonium cations, which is favorable for the formation of a CH´´´p interaction in crystal.