von Braun反應

利用溴化氰處理三級胺得到氰基胺和滷代烷的反應。本反應二級胺結果通常不好。通常脫落的基團是能夠生成最活潑的滷代烷的那個基團（如苄基或烯丙基），對於簡單烷烴，最小的基團最易離去，芳基不會離去。BrCN被稱為反撲試劑（counterattack reagent）即一種試劑在反應中實現所需的兩種轉化，生成產物。

反應機理

反應實例

參考文獻

1. von Braun, J. Ber. Dtsch. Chem. Ges. 1907, 40, 3914. Julius von Braun (1875􀀐1940)

was born in Warsaw, Poland. He was a Professor of Chemistry at Frankfurt.

2. Hageman, H. A. Org. React. 1953, 7, 198. (Review).

3. Fodor, G.; Abidi, S.-Y.; Carpenter, T. C. J. Org. Chem. 1974, 39, 1507.

4. Nakahara, Y.; Niwaguchi, T.; Ishii, H. Tetrahedron 1977, 33, 1591.

5. Fodor, G.; Nagubandi, S. Tetrahedron 1980, 36, 1279􀀐1300. (Review).

6. Perni, R. B.; Gribble, G. W. Org. Prep. Proced. Int. 1980, 15, 297.

7. Verboom, W.; Visser, G. W.; Reinhoudt, D. N. Tetrahedron 1982, 38, 1831.

8. McLean, S.; Reynolds, W. F.; Zhu, X. Can. J. Chem. 1987, 65, 200.

9. Cooley, J. H.; Evain, E. J. Synthesis 1989, 1.

10. Aguirre, J. M.; Alesso, E. N.; Ibanez, A. F.; Tombari, D. G.; Moltrasio Iglesias, G. Y.

J. Heterocycl. Chem. 1989, 26, 25.

11. Laabs, S.; Scherrmann, A.; Sudau, A.; Diederich, M.; Kierig, C.; Nubbemeyer, U.

Synlett 1999, 25.

12. Chambert, S.; Thomasson, F.; Décout, J.-L. J. Org. Chem. 2002, 67, 1898.

13. Hatsuda, M.; Seki, M. Tetrahedron 2005, 61, 9908.

編譯自：Name Reactions （A Collection of Detailed Reaction Mechanisms）, Jie Jack Li, von Braun reaction，page 608-609.