Gold(I)-Catalyzed Tandem Alkoxylation/Lactonization of γ-Hydroxy-α,β-Acetylenic Esters
作者:Rubén S. Ramón、Christophe Pottier、Adrián Gómez-Suárez、Steven P. Nolan
DOI:10.1002/adsc.201100115
日期:2011.6
The formation of 4‐alkoxy‐2(5H)‐furanones was achieved via tandem alkoxylation/lactonization of γ‐hydroxy‐α,β‐acetylenic esters catalyzed by 2 mol% of [2,6‐bis(diisopropylphenyl)imidazol‐2‐ylidine]gold bis(trifluoromethanesulfonyl)imidate [Au(IPr)(NTf2)]. The economic and simple procedure was applied to a series of various secondary propargylic alcohols allowing for yields of desired product of up
形成4-烷氧基-2-(5 ħ) -呋喃酮达到经由串联烷氧基化/γ-羟基-α内酯化,由2摩尔%的[2,6-双(二异丙基苯基)咪唑-2-催化β-炔酯-亚乙基]金双(三氟甲磺酰基)亚氨酸酯[Au(IPr)(NTf 2)]。将经济,简单的方法应用于一系列各种仲炔丙基醇,可实现高达95%的所需产物收率。另外,带有大部分环状取代基的叔炔丙基醇被转化为相应的螺衍生物。伯醇和仲醇均可在中等温度(65–80°C)下通过纯净反应或使用1,2-二氯乙烷作为反应介质与炔丙醇反应,收率达23–95%。与[Au(IPr)(NTf 2)]相反,与阳离子络合物如[2,6-双(二异丙基苯基)咪唑-2-基吡啶](乙腈)四氟硼酸金[Au(IPr)(CH 3 CN) ] [BF 4]或(μ-羟基)双[2,6-双(二异丙基苯基)咪唑-2-基吡啶]金}四氟硼酸酯或双(三氟甲磺酰基)亚氨酸酯– [Au(IPr)} 2(μ-OH)]