扎伊采夫(Zaitsev)消除规则
这主要是因为生成烯烃的稳定性不同:
但按理说更多的取代基造成临近的基团互相排斥,不是应该不稳定?超共轭效应是造成这种烯烃稳定性差异的主要原因之一,更多的取代基能提供更多超共轭的机会使电子离域(如下图示):
影响因素
一、离去基团
二、取代基
反应实例
参考文献
1. Aleksandr Mikhailovich Zaitsev (sometimes spelled as Saytseff, 1841–1910), like Markovnikov, was also a protégé of Aleksandr Mikhailovich Butlerov (1828–1882). But unlike Markovnikov’s lack of tact and inability to compromise with administrators, Zaitsev was a skilled politician. He held the position of chair at Kazan’ University for over four decades and educated a generation of organic chemistry.
2. Brown, H. C.; Wheeler, O. H. J. Am. Chem. Soc. 1956, 78, 2199–2210.
3. Chamberlin, A. R.; Bond, F. T. Synthesis 1979, 44–45.
4. Elrod, D. W.; Maggiora, G. M.; Trenary, R. G. Tetrahedron Comput. Methodol. 1990, 3, 163–174.
5. Larsen, N. W.; Pedersen, T. J. Mol. Spectrosc. 1994, 166, 372–382.
6. Reinecke, M. G.; Smith, W. B. J. Chem. Educ. 1995, 72, 541.
7. Guan, H.-P.; Ksebati, M. B.; Kern, E. R.; Zemlicka, J. J. Org. Chem. 2000, 65, 5177–5184.
8. Guan, H.-P.; Ksebati, M. B.; Kern, E. R.; Zemlicka, J. J. Org. Chem. 2000, 65, 5177-5184.
9. Hagen, T. J. Zaitsev Elimination, In Name Reactions for Functional Group Transformations; Li, J. J., Ed.; Wiley: Hoboken, NJ, 2007, pp 414-421. (Review).
10. Ramos, D. R.; Castillo, R.; Canle L., M.; Garcia, M. V.; Andres, J.; Santaballa, J. A. Org. Biomol. Chem. 2009, 7, 1807–1814. (Mechanism).
一、编译自:Name Reactions (A Collection of Detailed Reaction Mechanisms), Jie Jack Li, Zaitsev’s elimination rule,page 650-651.