Gold(I)-Catalyzed Cycloisomerization of 2-Fluoroalk-3-yn-1-ones: Synthesis of 2,5-Substituted 3-Fluorofurans
作者:Yan Li、Kraig A. Wheeler、Roman Dembinski
DOI:10.1002/adsc.201000411
日期:2010.11.2
4-disubstituted tert-butyldimethylsilyl but-1-en-3-yn-1-yl ethers with Selectfluor gives 2-mono-fluorobut-3-yn-1-ones. Subsequent 5-endo-dig cyclization in the presence of chlorotriphenylphosphine gold(I)/silver trifluoromethanesulfonate (both 5 mol%, dichloromethane) under ambient conditions, provides a facile method for the generation of mainly 2,5-diaryl-substituted 3-fluorofurans in high yields
用Selectfluor氟化1,4-二取代的叔丁基二甲基甲硅烷基丁基-1-en-3-yn-1-基醚,得到2-单氟丁基-3-yn-1- one 。在环境条件下,随后在氯三苯基膦金(I)/三氟甲磺酸银(均为5 mol%,二氯甲烷)存在下进行的5-内挖-环化,提供了一种简便的方法来生成主要被2,5-二芳基取代的3-氟呋喃高产(89-96%)。通过X射线晶体学确认2-(4-溴苯基)-3-氟-5-(4-甲基苯基)呋喃的结构。
Electrophilic Cyclizations of 2-Fluoroalk-3-yn-1-ones: Room-Temperature Synthesis of Diversely 2,5-Disubstituted 3,4-Fluorohalofurans
作者:Yan Li、Kraig A. Wheeler、Roman Dembinski
DOI:10.1002/ejoc.201100344
日期:2011.5
A 5-endo-dig halocyclization of 2-fluoroalk-3-yn-1-ones with the use of N-iodo- and N-bromosuccinimide, in the presence of gold chloride/zinc bromide (5:20 mol-%, dichloromethane), under ambient conditions, provides a facile method for the synthesis of 2,5-disubstituted 3-bromo-4-fluoro- and 3-fluoro-4-iodofurans. The sequential procedure starts at monofluorination of the alk-1-en-3-yn-1-yl silyl ethers