A New and Efficient Synthesis of 4-Functionalized Benzo[<i>b</i>]furans from 2,3-Dihalophenols
作者:Roberto Sanz、M. Pilar Castroviejo、Yolanda Fernández、Francisco J. Fañanás
DOI:10.1021/jo0508402
日期:2005.8.1
Tandem Sonogashira coupling/5-endo-dig cyclization reactions on 2,3-dihalophenols suppose a straightforward entry to 4-halobenzo[b]furans, which can be easily transformed into 4-functionalized benzo[b]furans, that are difficult to synthesize by other procedures. On the other hand, the starting 2,3-dihalophenols are efficiently prepared from commercially available 3-halophenols, via their N,N-diethyl
串联Sonogashira偶联/ 5-内切-挖上-2,3- dihalophenols环化反应假设一个简单的项,以4- halobenzo [ b ]呋喃,其可以容易地转化为4 -官能化苯并[ b ]呋喃,难以合成通过其他程序。另一方面,起始的2,3-二卤代苯酚是由市售的3-卤代苯酚经其N,N-二乙基氨基甲酸酯通过在低位用s -BuLi / TMEDA或LDA处理在2-位选择性锂化而有效制备的。温度和与卤素亲电子试剂的反应。