Organoboranes for synthesis. 9. Rapid reaction of organoboranes with iodine under the influence of base. a convenient procedure for the conversion of alkenes into iodides via hydroboration
作者:Herbert C. Brown、Michael W. Rathke、Milorad M. RogiC´、Norman R. De Lue
DOI:10.1016/s0040-4020(88)90010-5
日期:1988.1
sodium hydroxide. Organoboranes derived from terminal alkenes react with the utilization of approximately two of the three alkyl groups attached to boron, providing a maximum of 67% yield of alkyl iodide. Thus, hydroboration-iodination of 1-decene gives a 60% yield ofn-decyl iodide. Secondary alkyl groups, derived from internal alkenes, react more sluggishly and only one of the three alkyl groups attached
氢氧化钠可大大促进有机硼烷与碘的反应。衍生自末端烯烃的有机硼烷利用与硼相连的三个烷基中的大约两个进行反应,从而提供最高67%的烷基碘产率。因此,1-癸烯的硼氢化碘化得到正癸基碘化物的60%收率。衍生自内部烯烃的仲烷基反应较慢,并且与硼连接的三个烷基中只有一个被转化为碘化物。因此,应用于2-丁烯的方法提供了30%产率的2-丁基碘化物。使用二亚氨基硼烷双-(3-甲基-2-丁基硼烷,Sia 2BH)作为硼氢化剂可提高末端烯烃的碘化物收率,因为伯烷基优先于仲唾液酸基反应。因此,将1-癸烯与Sia 2 BH进行氢硼化,然后进行碘化,得到95%的正癸基碘化物。用甲醇的甲醇钠代替氢氧化钠可提供相当高的收率的烷基碘。在碱的存在下,硼氢化与碘化的结合为烯烃的抗-Markovnikov加氢碘化提供了一种方便的方法。与配置在反应中心的倒置有机硼烷进行的碱诱导的碘化,如通过形成内从三-2iodonorbomane外-降冰片基硼烷。