一种由2,3-二卤代苯酚高效合成4-官能化苯并[b]呋喃的新方法。

A new and efficient synthesis of 4-functionalized benzo[b]furans from 2,3-dihalophenols.

作者信息

Sanz Roberto, Castroviejo M Pilar, Fernández Yolanda, Fañanás Francisco J

机构信息

Departamento de Química, Area de Química Orgánica, Facultad de Ciencias, Universidad de Burgos, Pza. Missael Bañuelos s/n, 09001-Burgos, Spain.

出版信息

J Org Chem. 2005 Aug 5;70(16):6548-51. doi: 10.1021/jo0508402.

DOI:10.1021/jo0508402

PMID:16050730

Abstract

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 carbamates by selective lithiation at the 2-positions by treatment with s-BuLi/TMEDA or LDA at low temperature and reaction with halogen electrophilic reagents.

摘要

在2,3-二卤代苯酚上进行串联Sonogashira偶联/5-内型-亲核环化反应为合成4-卤代苯并[b]呋喃提供了一条直接的途径，4-卤代苯并[b]呋喃可以很容易地转化为4-官能化苯并[b]呋喃，而通过其他方法很难合成这些化合物。另一方面，起始原料2,3-二卤代苯酚可由市售的3-卤代苯酚通过其N,N-二乙基氨基甲酸酯高效制备，方法是在低温下用仲丁基锂/四甲基乙二胺（s-BuLi/TMEDA）或二异丙基氨基锂（LDA）在2-位进行选择性锂化，然后与卤代亲电试剂反应。