[English name] allyltrimethylsilane
[Formula] c6h14si
[molecular weight] 114.27
[Ca login No.] [762-72-1]
[structural formula] H2C = chch2sime3
[physical properties] BP 84 ~ 88 OC, D 0.719 g / cm3. It is soluble in most organic solvents and is usually used in CH2Cl2, THF and MeCN.
[preparation and commodity] the reagent is sold by chemical reagent companies at home and abroad. It can be prepared by reaction of trimethylchlorosilane with allyl Grignard reagent in the laboratory [1].
[note] the reagent is highly natural and volatile, and the steam has unpleasant smell and corrosiveness. It is recommended to operate and use in fume hood.
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Allyltrimethylsilane is defined as an excellent nucleophilic reagent in organic synthesis. In the presence of Lewis acid catalyst, allyltrimethylsilane can react with many substrate molecules and introduce allyl functional groups into the substrate molecules. The nucleophilic reactions of the reagent with aldehydes, acetal derivatives, alkenyl ammonium ions and α, β - unsaturated ketones are widely used.
Allyltrimethylsilane, as a nucleophile, its double bond end carbon atom is first attacked by the electrophilic reagent to form a carbon cation intermediate. Then, the trimethylsilyl group is lost to form a new terminal double bond. Compared with the double bond in n-propene, the nucleophilic ability of allyltrimethylsilane is about 105 times higher [2]. Allyltrimethylsilane can react with aldehydes to form nucleophilic addition products. A Lewis acid catalyst is needed for this reaction, and many different kinds of Lewis acids can be used for this purpose. The yield and stereoselectivity of the product are mainly affected by the type of catalyst and the structure of the substrate (formula 1) [3,4].
The reaction of allyltrimethylsilane with acetal derivatives has a high value of synthesis. The ester of cyclic acetal or cyclic semiacetal can selectively introduce allyl group into the ring. BF3. Et2O [5], TMSOTf [6] and Ti (o-ipr) 2Cl2 [7] are commonly used Lewis acid catalysts. The reaction conditions are very mild, and generally have no obvious effect on other functional groups (formula 2, formula 3).
Under the action of Lewis acid catalyst, the cyclic amines with hydroxyl or halogen in the ortho position can form relatively stable alkenyl ammonium ions. They are attacked by allyltrimethylsilane nucleophilic, and allyl (formula 4) [8,9] is introduced on the ring.
The Michael addition reaction between allyltrimethylsilane and α, β - unsaturated ketone is expected. The reaction can easily introduce allyl at β - position of carbonyl (formula 5) [10,11].
The reaction of allyltrimethylsilane with α - alkynol to produce the corresponding alkynyl compound is very meaningful (formula 6) [12,13], because the product of the reaction can undergo subsequent alkynyl reaction, for example, olefin metathesis reaction. Recently, it has been reported that under the action of Grubbs catalyst, allyl three methylsilane can undergo cross olefin metathesis reaction with other suitable olefins [14].
reference
1. Sommer, L. H.; Tyler, L. J.; Whitmore, F. C. J. Am. Chem. Soc., 1948, 70, 2872.
2. Hagen, G.; Mayr, H. J. Am. Chem. Soc., 1991, 113, 4954.
3. Nosse, B.; Chhor, R. B.; Jeong, W. B.; Bohm, C.; Reiser, O. Org. Lett., 2003, 5, 941.
4. Keum, G.; Kang, S. B.; Kim, Y.; Lee, E. Org. Lett., 2004, 6, 1895.
5. Jiang, L.; Martinelli, J. R.; Burke, S. D. J. Org. Chem., 2003,68, 1150.
6. Piper, J. L.; Postema, M. H. D. J. Org. Chem., 2004, 69, 7395.
7. Hornberger, K. R.; Hamblett, C. L.; Leighton, J. L. J. Am. Chem. Soc., 2000, 122, 12894.
8. Burgess, K. L.; Lajkiewicz, N. J.; Sanyal, A.; Yan, W.; Snyder, J. K. Org. Lett., 2005, 7, 31.
9. Bull, S. D.; Davies, S. G.; Garner, A. C.; Savory, E. D.; Snow, E. J.; Smith, A. D. Tetrahedron: Asymmetry, 2004, 15, 3989.
10. Muratake, H.; Natsume, M.; Nakai, H. Tetrahedron, 2004, 60, 11783.
11. Perron, J.; Joseph, B.; Merour, J.-Y. Tetrahedron, 2004, 60, 10099.
12. Schwier, T.; Rubin, M.; Gevorgyan, V. Org. Lett., 2004, 6, 1999.
13. Luzung, M. R.; Toste, F. D. J. Am. Chem. Soc., 2003, 125, 15760.
14. Jung, J.; Shin, D.; Seo, S.; Kim, S.; Paek, S.; Jung, J.; Suh, Y. Tetrahedron Lett., 2005, 46, 573.
This paper is from: modern organic synthetic reagents -- properties, preparation and reaction, edited by Hu Yuefei, et al
Related reaction
Hosomi Sakurai reaction
michael reaction
Olefin metathesis