Nickel-Catalyzed Carbocyanation of Alkynes with Allyl Cyanides
Nickel-Catalyzed Carbocyanation of Alkynes with Allyl Cyanides
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DOI：
10.1021/ja901374v
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发表时间：
2009-08-12
影响因子：
15
通讯作者：
Hiyama, Tamejiro
中科院分区：
文献类型：
--
作者：
Hirata, Yasuhiro;Yukawa, Tomoya;Hiyama, Tamejiro
在镍/P（4-CF_3-C_6 H_4）（3）催化剂存在下，烯丙基氰与炔发生加成反应，生成具有一定立体化学和区域化学的多取代2，5-己二烯腈。使用AlMe 2 Cl或AlMe 3作为刘易斯酸助催化剂可加速反应并显著扩大底物范围。烯丙基氰化产物中的氰基可转化为羟甲基或氨甲基，得到高度取代的烯丙醇或胺。α-甲硅烷氧基烯丙基氰化物也在受阻较少的γ-碳上选择性地加成炔，以允许在所得甲硅烷基烯醇醚水解后引入3-氧代-丙基官能团。这种特殊的碳氰化反应已被应用于立体选择性建设的三取代双键的plaunotol，抗菌天然产物活性对幽门螺杆菌。
Allyl cyanides are found to add across alkynes in the presence of a nickel/P(4-CF3-C6H4)(3) catalyst to give polysubstituted 2,5-hexadienenitriles with defined stereo- and regiochemistry. Use of AlMe2Cl or AlMe3 as a Lewis acid cocatalyst accelerates the reaction and expands the substrate scope significantly. The cyano group in the allylcyanation products can be transformed to a hydroxymethyl or aminomethyl group to afford highly substituted allylic alcohols or amines. alpha-Siloxyallyl cyanides also add across alkynes selectively at the less hindered gamma-carbon to allow introduction of 3-oxo-propyl functionality after hydrolysis of the resulting silyl enol ethers. This particular carbocyanation reaction has been applied to the stereoselective construction of the trisubstituted double bond of plaunotol, an antibacterial natural product active against Helicobacter pylori.