A convenient synthesis of (S)-2-Azidonitriles, (S)-2-aminonitriles and (S)-1,2-diamines
作者:F. Effenberger、Andreas Kremser、Uwe Stelzer
DOI:10.1016/0957-4166(96)00044-4
日期:1996.2
(S)-2-Azidonitriles (S)-4 are easily accessible from (R)-2-(sulfonyloxy)nitriles (R)-2 by nucleophilic substitution with alkali azides 3 under complete inversion of configuration. The azidonitriles (S)-4 can be converted by catalytic hydrogenation into (S)-2-aminonitriles (S)-8 and by hydrogenation using LiAlH4 into (S)-1, 2-diaminoalkanes (S)-9, respectively, both, (S)-8 and (S)-9, isolated as hydrochlorides. Hydrolysis of the aminonitrile hydrochlorides (S)-8 HCl in a saturated solution of HC1 in alcohol gives (S)-2-amino carboxamide hydrochlorides(S)-10 . HCl with enantiomeric excesses >99% after recrystallization.
Asymmetric Strecker Reaction of Aldimines Using Aqueous Potassium Cyanide by Phase-Transfer Catalysis of Chiral Quaternary Ammonium Salts with a Tetranaphthyl Backbone
作者:Takashi Ooi、Yukitaka Uematsu、Keiji Maruoka
DOI:10.1021/ja058066n
日期:2006.3.1
protected amino nitrile (R = c-Hex) in 89% yield with 95% ee. A wide range of aliphatic aldimines, including those having alpha-tert-alkyl substituents, is tolerated by the present system. This study represents a novel approach for the asymmetric Strecker-type reactions, which utilizes chiral phase-transfer catalysts for practical access to various unusual, optically pure alpha-amino acids.