三甲基碘硅烷脱甲基反应

三甲基碘硅烷脱甲基是通过芳基甲醚与三甲基碘硅烷生成芳基硅醚，水解得到脱甲基产物。一种常用的脱甲基试剂，在此体系中，双键、三键、酮羰基、氨基和卤代物稳定，但苄醚、三苯甲基醚、叔丁基醚不稳定。三甲基碘硅烷能裂解酯但比醚慢。此试剂实验室可以用多种方法来制备，建议使用以六甲基二硅烷和碘单质为原料的制备方法，该方法得到的产物纯度较高【J. Org. Chem., 1995, 60, 4617】。在许多时候也可以使用三甲基氯硅烷与NaI 或者LiI 在反应前原位生成三甲基碘硅烷，但是这样生成的试剂的反应活性可能较低。

反应机理

由于氧与硅的结合能力较强，容易形成氧鎓离子，碘离子亲核取代生成芳基硅醚，水解得到产物。

反应实例

【J. Chem. Res., 2009 , 4 , 229-230】

General Procedure forDealkylation of Ether.  To a 2 M solution of ether (1 equiv.) in a suitable solvent (Table 10) is added neattrimethylsilyl iodide (1.3 equiv.) through a dry syringe. The reaction is maintained at temperature indicated in Table 10 and monitored by NMR forcompletion. Yields are calculated by NMR integration of pertinent peaks. Forisolation of the alcohols, at the completion of the reaction, the excesstrimethylsilyl iodide is destroyed and the intermediate trimethylsilyl etherformed during the reaction is hydrolyzed to alcohol by pouring the reactionmixture into methanol (4 equiv.). The volatile components are removed atreduced pressure and the residue is taken up in ether, washed with aqueoussodium bisulfite, aqueous sodium bicarbonate and brine and dried. The residueleft after evaporation of solvent is further purified (if necessary) by columnchromatography on silica gel.

【J. Org. Chem., 1977, 42, 3761】

【Org. Lett., 2005, 7, 123】