Palladium(II)-Catalyzed Oxidative Transformation of Allylic Alcohols and Vinyl Ethers into 2-Alkoxytetrahydrofurans: Catechol as an Activator of Catalyst
作者:Kimi Minami、Yasufumi Kawamura、Koichi Koga、Takahiro Hosokawa
DOI:10.1021/ol052377l
日期:2005.12.1
[chemical reaction: see text]. A highly effective synthesis of 2-alkoxytetrahydrofurans from allylic alcohols and vinyl ethers was achieved by using catalytic amounts of Pd(OAc)2, Cu(OAc)2, and catechol (1:1:2) under O2. The use of catechol as an activator of Pd(II)-Cu(II) catalyst has been unprecedented. The 2-alkoxytetrahydrofurans are formed via oxypalladation of allylic alcohols toward vinyl ethers
[化学反应:见正文]。通过在O2下使用催化量的Pd(OAc)2,Cu(OAc)2和邻苯二酚(1:1:2),可以从烯丙基醇和乙烯基醚高效合成2-烷氧基四氢呋喃。使用邻苯二酚作为Pd(II)-Cu(II)催化剂的活化剂是前所未有的。该2-烷氧基四氢呋喃是通过将烯丙醇向乙烯基醚的氧化钯反应,然后对所得的氧化钯中间体进行5-外环环化并随后进行β-Pd-H消除而形成的。氧化palpalation中间体没有发生6-endo环化。