作者:Jae Sang Yi、Kyongtae Kim
DOI:10.1039/a806192k
日期:——
Treatment of 7-phenylseleno-7,12-dihydrobenzo[5,6][1,3]thiazepino[3,2-a]benzimidazole 6,6-dioxide 7a in CH2Cl2 with m-chloroperbenzoic acid (MCPBA) and 28% H2O2 at room temperature gave Se-phenyl 2-[(benzimidazol-1-yl)methyl]selenobenzoate 8a. Similarly, the oxidation of sulfone 7a in THF with aqueous Oxone® at room temperature gave the same selenolester 8a. The formation of selenolesters 8 can be explained by assuming either the involvement of oxaseleniranium cation 13, having a sulfinate group at C-2 of the benzimidazole moiety, as an intermediate which is believed to be formed by an intramolecular nucleophilic attack of the polarized oxygen of the SeO bond of selenoxide 6 to the α-carbon next to the sulfonyl group, or Pummerer-type reactions.
用间氯过苯甲酸 (MCPBA) 和 28% H2O2 在 CH2Cl2 中处理 7-苯基硒基-7,12-二氢苯并[5,6][1,3]硫氮杂[3,2-a]苯并咪唑 6,6-二氧化物 7a在室温下得到2-[(苯并咪唑-1-基)甲基]硒代苯甲酸硒苯酯8a。类似地,在室温下用Oxone 水溶液在THF 中氧化砜7a 得到相同的硒醇酯8a。硒醇酯 8 的形成可以通过假设氧杂硒鎓阳离子 13 的参与来解释,该阳离子 13 在苯并咪唑部分的 C-2 处具有亚磺酸盐基团,作为中间体,据信该中间体是通过极化氧的分子内亲核攻击形成的。氧化硒 6 的 SeO 键与磺酰基旁边的 α-碳键合,或称 Pummerer 型反应。