Cui Xiaoyan, Sun Can, Zhao Pei, Wang Yanyan, Guo Yanchun, Zhao Yufen, Cao Shuxia
College of Chemistry and Molecular Engineering, Key Laboratory of Chemical Biology and Organic Chemistry of Henan Province, Zhengzhou University, Zhengzhou, 450052, China.
Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, 100084, China.
J Mass Spectrom. 2018 Apr;53(4):314-322. doi: 10.1002/jms.4064.
The fragmentation pathways of pentacoordinated phenoxyspirophosphoranes were investigated in the positive mode by electrospray ionization multistage mass spectrometry. The results demonstrate that the sodium adducts of the title compounds undergo two competitive fragmentation pathways, and the fragmentation patterns are heavily dependent on the various substituent patterns at the phenolic group. An electron-withdrawing substituent at the ortho-position always results in the removal of a corresponding phenol analogue, while cleavage by spiroring opening becomes the predominant fragmentation pathway if an electron-donating substituent is at the phenolic group. The substituent effects on the competitive fragmentation pathways were further elucidated by theoretical calculations, single crystal structure analysis, and high-resolution mass spectrometry. The results contribute to the understanding of the gas-phase fragmentation reactions and the structure identification of spirophosphorane analogues by electrospray ionization multistage mass spectrometry.
通过电喷雾电离多级质谱法在正模式下研究了五配位苯氧基螺磷杂环戊烷的碎裂途径。结果表明，标题化合物的钠加合物经历两种竞争碎裂途径，且碎裂模式在很大程度上取决于酚羟基上的各种取代基模式。邻位的吸电子取代基总是导致相应酚类似物的消除，而如果酚羟基上存在供电子取代基，则螺环开环裂解成为主要的碎裂途径。通过理论计算、单晶结构分析和高分辨率质谱进一步阐明了取代基对竞争碎裂途径的影响。这些结果有助于通过电喷雾电离多级质谱理解气相碎裂反应以及螺磷杂环戊烷类似物的结构鉴定。
