The radical bromoallylation of alkynes, allenes, and vinylidene cyclopropanes proceeds efficiently in the presence of a radical initiator to give 2-bromo-substituted 1,4-, 1,5-, and 1,6-diene derivatives, respectively. Three-component reactions comprised of allenes, electron-deficient alkenes, and allyl bromides give 1,7-dienes in good yields. The bromoallylation of an arylalkene can override β-scission of the bromine radical from β-bromoalkyl radicals to give 5-bromoalkenes, whilst the bromoallylation of vinylcyclopropanes is accompanied by 5-exo ring closure to give 1-(bromomethyl)-2-vinylcyclopentane derivatives in good yields. All of the products contain a reactive vinyl bromide moiety, which can be readily functionalized by Pd-catalyzed cross-coupling and radical cascade reactions.

1 Introduction

2 Synthesis of 1,4-Dienes by Bromoallylation of Acetylenes

3 Synthesis of 1,5-Dienes by Bromoallylation of Allenes

4 Synthesis of 1,6-Dienes by Bromoallylation of Methylenecyclopropanes

5 Synthesis of 1,7-Dienes by Bromoallylation of Allenes and Electron-Deficient Alkenes

6 Bromoallylation of Arylalkenes and Vinylcyclopropanes

7 Conclusion

炔烃、丙二烯和亚乙烯基环丙烷的自由基溴代烯丙基化在自由基引发剂存在下有效进行，分别产生 2-溴取代的 1,4-、1,5- 和 1,6-二烯衍生物。由丙二烯、缺电子烯烃和烯丙基溴组成的三组分反应以良好的收率生成 1,7-二烯。芳基烯烃的溴代烯丙基化可以覆盖β-溴代烷基的溴基的β-断裂，得到5-溴代烯烃，而乙烯基环丙烷的溴代烯丙基化伴随着5-外环闭合，得到1-(溴甲基)-2-乙烯基环戊烷衍生物在良好的产量。所有产品都包含一个反应性溴乙烯部分，可以很容易地通过 Pd 催化的交叉偶联和自由基级联反应进行功能化。

1 简介

2 乙炔溴烯丙基化合成1,4-二烯

3 丙二烯溴烯丙基化合成1,5-二烯

4 亚甲基环丙烷溴烯丙基化合成1,6-二烯

5 丙二烯和缺电子烯烃溴烯丙基化合成1,7-二烯

6 芳基烯烃和乙烯基环丙烷的溴烯丙基化

7 结论