醚类和三甲基碘硅烷在非质子溶剂中(如四氯化碳,二氯甲烷,氯仿等等)反应生成硅醚和碘代烃。除了醚可以裂解,甲酯和乙酯,氨基甲酸酯,膦酸酯,也可以裂解。
该反应可在中性条件下数分钟至数小时内完成,即使甲基醚也给出很好的结果。烷基被断裂的次序是:叔烃基 >苄基 >烯丙基 >仲烃基 >伯烃
基 (式1)[2,3]。酚醚一般需要较高的温度和较长的时间,生成酚和碘代烃。
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。
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
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.
【M. E. Jung and M. A.Lyster, J. Org. Chem., 1977, 42, 3761】
【Org. Lett., 2005, 7, 123.】
【J. Am. Chem. Soc., 2005, 127, 7334】
【J. Chem. Res., 2009 , 4 , 229- 230.】
相关文献
1 Voronkov MG Zh Obshch Khim 1976 46 1908
2 Olah GA Angew Chem Int 1976 15 774
3 Jung ME J Am Chem Soc 1977 99 968
4 Jung ME J Org Chem 1977 42 3761
5 Olah GA Synthesis 1977 581
6 Jung ME Chem Comm 1978 315
7 Olah GA Tetrahedron 1982 38 2225
8 Hanessian S Tet Lett 1984 25 2515
9 Jung ME Org Synth Coll 1988 6 353
10 Nishida A Eur J Org Chem 2006 752
参考文献
Organic Syntheses Based On Name Reactions, 3RdEd, A. Hassner, Page 234.
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