Eschenmoser盐，N,N-二甲基亚甲基碘化铵，是一种很强的二甲基胺甲基化试剂，用于合成含有RCH2N(CH3)2结构的化合物。烯醇化合物，烯醇硅醚，甚至酸性较强的酮都可很好的进行二甲基胺甲基化，得到与Mannich 反应相同的产物。

反应机理

反应实例

反应完成后得到的叔胺产物，进一步甲基化，碱催化下消除得到亚甲基羰基化合物。

参考文献

1. Schreiber, J.; Maag, H.; Hashimoto, N.; Eschenmoser, A. Angew. Chem. Int. Ed. 1971,10, 330–331. Albert Eschenmoser (Switzerland, 1925) is best known for his work on,among many others, the monumental total synthesis of Vitamin B12 with R. B. Woodward in 1973. He now holds joint appointments at ETH Zürich and Scripps ResearchInstitute, La Jolla.

2. Kleinman, E. F. Dimethylmethyleneammonium Iodide and Chloride. In Encyclopedia of Reagents for Organic Synthesis (Ed: Paquette, L. A.) 2004, WileyNew York. (Review).

3. Nicolaou, K. C.; Reddy, K. R.; Skokotas, G.; Sato, F.; Xiao, X. Y.; Hwang, C. K. J. Am. Chem. Soc. 1993, 115, 3558–3575.

4. Lidia Kupczyk-Subotkowska, L.; Shine, H. J. J. Labelled Compd. Radiopharm. 1993, 33, 301 304.

5. Saczewski, J.; Gdaniec, M. Tetrahedron Lett. 2007, 48, 7624–7627.

6. Hong, A.-W.; Cheng, T.-H.; Raghukumar, V.; Sha, C.-K. J. Org. Chem. 2008, 73, 7580–7585.

7. Cesario, C.; Miller, M. J. Org. Lett. 2009, 11, 449–452.

8. Crimmins, M. T.; Zuccarello, J. L.; Ellis, J. M.; McDougall P. J.; Haile, P. A.; Parrish,J. D.; Emmitte, K. A. Org. Lett. 2009, 11, 489-492.

编译自：J.J. Li, Name Reactions: A Collection of Detailed Mechanisms and Synthetic Applications, Eschenmoser’s salt，page 231-232.