Hirata Yasuhiro, Yukawa Tomoya, Kashihara Natsuko, Nakao Yoshiaki, Hiyama Tamejiro
Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan.
J Am Chem Soc. 2009 Aug 12;131(31):10964-73. doi: 10.1021/ja901374v.
Allyl cyanides are found to add across alkynes in the presence of a nickel/P(4-CF(3)-C(6)H(4))(3) catalyst to give polysubstituted 2,5-hexadienenitriles with defined stereo- and regiochemistry. Use of AlMe(2)Cl or AlMe(3) 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.
发现烯丙基腈在镍/三（4-三氟甲基苯基）膦催化剂存在下与炔烃加成，生成具有特定立体化学和区域化学的多取代2,5-己二烯腈。使用二甲基氯化铝或三甲基铝作为路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，以得到高度取代的烯丙醇或胺。α-硅氧基烯丙基腈也在空间位阻较小的γ-碳处选择性地与炔烃加成，从而在所得硅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应用于对幽门螺杆菌具有活性的抗菌天然产物普劳诺托的三取代双键的立体选择性构建。
