Resolution and Rotational Barriers of Quinolinone and Acridone Sulfenamide Derivatives: Demonstration of the S−N Chiral Axis
作者:Merav Ben-David Blanca、Chiyo Yamamoto、Yoshio Okamoto、Silvio E. Biali、Daniel Kost
DOI:10.1021/jo001041g
日期:2000.12.1
ridone derivatives were synthesized. Addition of the chiral solvating agent (S)- 2,2,2-trifluro-1-(anthryl)ethanol to 8a rendered the enantiotopic groups on the acridone ring diastereotopic and anisochronous, thus allowing the estimation of a lower limit for the rotational barrier about the S-N bond (18.7 kcal mol(-)(1)) by NMR spectroscopy. 8b and the previously reported chiral sulfenamide 5 (Raban
合成了非手性(8a)和手性(8b)N-(2,4-二硝基苯硫基)ac啶酮衍生物。向8a中加入手性溶剂化剂(S)-2,2,2,2-三氟-1-(蒽基)乙醇使得rendered啶酮环上的对映异构基团是非对映异构的,并且是等时的,因此可以估算旋转势垒的下限通过NMR光谱了解SN键(18.7 kcal mol(-)(1))。在Chiracel OD HPLC柱上解析图8b和先前报道的手性亚磺酰胺5(Raban,M。; Martin,VA; Craine,LJ Org.Chem.1990,55,4311)。这构成了化合物的立体稳定对映异构体的第一分辨率,其中手性仅由于SN手性轴的存在。两种化合物的旋转势垒在303处几乎相等(22.7-22。8 kcal mol(-)(1)。是亚磺酰胺中围绕SN键旋转迄今为止确定的最大值。由于8b的周围位置未被取代,因此8b的相对较高的对映异构势垒非常显着。