A New Facile Approach to the Synthesis of 3-Methylthio-Substituted Furans, Pyrroles, Thiophenes, and Related Derivatives
作者:Guodong Yin、Zihua Wang、Aihua Chen、Meng Gao、Anxin Wu、Yuanjiang Pan
DOI:10.1021/jo702585s
日期:2008.5.1
the Paal−Knorr furan synthesis. Meanwhile, 4-bromo-3-methylthio 2,5-diaryl furan 10 is obtained either by the treatment of furan 7 with molecular bromine or by the treatment of diketone 3 with 30% hydrogen bromide in acetic acid solution in one pot. Removal of the methylthio group is accomplished by the treatment of 7 with Raney Ni in ethanol, which affords the diaryl-substituted furan 11 in excellent
2-(甲硫基)-1,4-二芳基-2-丁烯-1,4-二酮(3)是在氧化铜(II),碘和二甲基亚砜存在下,由易得的芳基甲基酮制得的。4-氯苯乙酮与2-乙酰基噻吩交叉偶联反应的成功证实了提出的自分选串联反应机制。既ž -和Ë化合物-异构体3被容易地转化为相应的3-甲硫基-2,5-二芳基呋喃7通过涉及双键随后帕尔-克诺尔呋喃合成减少多米诺过程以良好的收率。同时,通过处理呋喃7可得到4-溴-3-甲硫基2,5-二芳基呋喃10。用分子溴或一锅中用30%溴化氢在乙酸溶液中的二酮3处理。甲硫基的除去是通过在乙醇中用阮内镍处理7来完成的,从而以优异的分离产率得到了二芳基取代的呋喃11。化合物3的双键的选择性还原导致形成饱和的1,4-二酮13,可通过Paal-轻松将其转化为相应的3-甲硫基-2,5-二芳基取代的吡咯14和噻吩15家乐环化反应。