Evidence for competitive intramolecular trimethylsilyl rearrangement to oxygen and sulfur in beta-trimethylsilylethylthiolesters.
Evidence for competitive intramolecular trimethylsilyl rearrangement to oxygen and sulfur in beta-trimethylsilylethylthiolesters.
复制标题
β-三甲基甲硅烷基乙基硫醇酯中氧和硫的竞争性分子内三甲基甲硅烷基重排的证据。
DOI：
10.1002/rcm.1290020206
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Fuchs,PL
中科院分区：
文献类型：
--
作者：
Wood,KV;Rothwell,AP;Anderson,MB;Fuchs,PL
2-（三甲基甲硅烷基）乙醇是用于内酯的间接皂化的众所周知的试剂，以及羧基、233氨基和羟基的保护基。有机合成中的基团。类似的β-2-三甲基甲硅烷基乙基硫醇试剂8对于硫部分的亲电和亲核引入具有潜在的效用。在完整的光谱表征的过程中，这些betrimethylsilylthiolesters和比较它们的氧类似物，观察到一些有趣的质谱碎片。硫酯的化学电离质谱中含有碎片离子，表明存在六中心三甲基硅基到氧和四中心三甲基硅基到硫过渡态之间的竞争。在电子电离和化学电离中都观察到了三甲基硅基的重排。~质谱。这些重排可以发生在典型的McLaffe型六中心跃迁到~氧、~、~以及到其它杂原子中
2-(Trimethylsilyl) ethanol is a well-known reagent for the indirect saponification of lactones' as well as a protecting group for carboxy, 233 am in^^,^ and hydr~ xy".~ groups in organic synthesis. The analogous beta-2-trimethylsilylethylthiol reagent8 has potential utility for both electrophilic and nucleophilic introduction of the sulfur moiety. In the course of complete spectroscopic characterization of these betatrimethylsilylthiolesters and comparing them to the oxygen analogs, some interesting mass spectral fragmentations were observed. The chemical ionization mass spectra of the thiolesters contained fragment ions which suggested that there existed a competition between a six-centered trimethyisilyl-to-oxygen, and a four-centered trimethylsilyl-to-sulfur transition state. Rearrangement of the trimethylsilyl moiety has been observed in both electron ionization,"-'3 and chemical ioni~ ation'~.'~ mass spectra. These rearrangements can occur in typical McLafferty type six-centered transitions to~ xygen,'",'~ as well as to other heteroatoms