Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka 565-0871, Japan.
J Org Chem. 2011 Aug 5;76(15):6277-85. doi: 10.1021/jo2010632. Epub 2011 Jul 1.
Chiral quaternary ammonium salt-catalyzed diastereoselective aziridination of electron-deficient olefins that possess a chiral auxiliary with N-chloro-N-sodiocarbamates was developed. The key to high stereoselectivity was found to be the employment of the "matching" stereochemical combination of chiral auxiliary/ammonium salt. For example, when 3-phenyl-(4R,7S)-4-methyl-7-isopropyl-4,5,6,7-tetrahydroindazole (L-menthopyrazole) as a chiral auxiliary and a cinchonidine-derived chiral ammonium salt as a catalyst were applied to the reaction system, perfect diastereoselectivity was realized. Furthermore, the preparation of enantiomerically pure aziridines by removal of the chiral auxiliary was demonstrated.
手性季铵盐催化的缺电子烯烃的非对映选择性环氧化反应，其中具有手性辅基的 N-氯代-N-磺酸钠被开发出来。高立体选择性的关键是采用“匹配”的手性辅基/铵盐的立体化学组合。例如，当 3-苯基-(4R,7S)-4-甲基-7-异丙基-4,5,6,7-四氢吲哚（L-薄荷吡唑）作为手性辅基和金鸡纳衍生的手性铵盐作为催化剂应用于反应体系时，实现了完美的非对映选择性。此外，通过去除手性辅基来制备对映体纯的氮丙啶也得到了证明。
