Pd(OAc)<sub>2</sub>/P(<i><sup>c</sup></i>C<sub>6</sub>H<sub>11</sub>)<sub>3</sub>-Catalyzed Allylation of Aryl Halides with Homoallyl Alcohols via Retro-Allylation
作者:Masayuki Iwasaki、Sayuri Hayashi、Koji Hirano、Hideki Yorimitsu、Koichiro Oshima
DOI:10.1021/ja067372d
日期:2007.4.1
fashion via a conformationally regulated six-membered cyclic transition state, the allylation reactions are highly regio- and stereospecific when homoallyl alcohols having a substituted allyl group are used. Whereas triarylphosphine is known to serve as a ligand for the palladium-catalyzed allyl transfer reactions, tricyclohexylphosphine proves to significantly expand the scopes of aryl halides to electron-rich
在碳酸铯和钯催化剂存在下用芳基卤处理叔高烯丙醇时发生芳基卤的烯丙基化。烯丙基化反应将由以下步骤组成:(1)芳基卤化物与钯的氧化加成,(2)卤化物和高烯丙醇之间的配体交换,提供芳基(高烯丙氧基)钯,(3)钯醇盐的逆烯丙基化生成σ-烯丙基(芳基)钯,同时释放相关酮,和 (4) 生产性还原消除。由于逆烯丙基化步骤通过构象调节的六元环状过渡态以协同方式进行,因此当使用具有取代烯丙基的高烯丙醇时,烯丙基化反应具有高度的区域和立体定向性。虽然已知三芳基膦可作为钯催化的烯丙基转移反应的配体,但三环己基膦证明可以将芳基卤化物的范围显着扩展到富电子的芳基氯化物,将高烯丙醇的范围扩大到环状高烯丙醇。环状高烯丙醇的新芳基化开环反应允许以区域和立体特异性方式合成在远端具有支化或线性烯丙基芳烃部分的酮。