Selective Synthesis and Structural Elucidation of <i>S</i>-Acyl- and <i>N</i>-Acylcysteines
作者:Alan R. Katritzky、Srinivasa R. Tala、Nader E. Abo-Dya、Kapil Gyanda、Bahaa El-Dien M. El-Gendy、Zakaria K. Abdel-Samii、Peter J. Steel
DOI:10.1021/jo900853s
日期:2009.9.18
N-(Acyl)-1H-benzotriazoles 6a−f react with l-cysteine 5 at 20 °C to give exclusively (i) N-acyl-l-cysteines 8a−e in the presence of triethylamine in CH3CN−H2O (3:1), but (ii) S-acyl-l-cysteines 7a−e in CH3CN−H2O (5:1) in the absence of base. Structures 7b, 7d and 8b, 8d are supported by 2D NMR spectroscopic methods including gDQCOSY, gHMQC, gHMBC, and 1H−15N CIGAR-gHMBC experiments. The structure of
N-(酰基)-1 H-苯并三唑6a - f在20°C下与1-半胱氨酸5反应,仅在CH 3 CN-H中存在三乙胺的情况下仅生成(i)N-酰基-1-半胱氨酸8a - e 2 O(3:1),但(ii)CH 3 CN-H 2 O(5:1)中在不存在碱的情况下的S-酰基-1-半胱氨酸7a - e。结构7b,7d和8b,8d支持2D NMR光谱方法,包括gDQCOSY,gHMQC,gHMBC和1 H - 15 N CIGAR-gHMBC实验。化合物8d的结构也通过单晶X射线衍射来支撑。