Photochemistry of phthaloylcysteine, its methyl ester and C-unprotected S-alkyl derivatives
作者:Axel G. Griesbeck、Joachim Hirt、Wolfgang Kramer、Paul Dallakian
DOI:10.1016/s0040-4020(98)00063-5
日期:1998.3
cysteine derivatives 1a-d were photochemically transformed by elimination, decarboxylation, and via electron transfer cyclization to the products 2,3,4 and 6–8. The spin selectivities of singlet and triplet pathways were investigated in acetonitrile and acetone. The excited singlets were prone to elimination and γ-H abstractions (e.g. formation of 5) whereas the triplets cyclized to thiazinoisoindoles
N-邻苯二甲酰基半胱氨酸衍生物1a-d通过消除,脱羧和通过电子转移环化而光化学转化为产物2,3,4和6-8。在乙腈和丙酮中研究了单重态和三重态途径的自旋选择性。激发的单线态易于消除和γ-H提取(例如形成5),而三联体环化成噻嗪基异吲哚。该行为可以与正向和返回电子转移步骤相对于均质氢提取的效率相关,如半胱氨酸底物9所证明的。