Controlled Synthesis of 2- and 3-Substituted Benzo[<i>b</i>]furans
作者:Tao Pei、Cheng-yi Chen、Lisa DiMichele、Ian W. Davies
DOI:10.1021/ol102123u
日期:2010.11.5
A controlled regioselective synthesis of either C-2 or C-3 substituted benzo[b]furans from readily accessible 1-(2-hydroxyphenyl)-2-chloroethanones is described. Addition of a range of Grignard reagents to the α-chloro ketones generates alkoxide intermediates, which can form either 2-substituted benzo[b]furans via a [1,2]-arylmigration or 3-substituted benzo[b]furans via a direct cyclization and dehydration
描述了从容易获得的1-(2-羟苯基)-2-氯乙酮的C-2或C-3取代的苯并[ b ]呋喃的受控区域选择性合成。在α-氯代酮中添加一系列格氏试剂可生成醇盐中间体,该中间体可通过[1,2]-芳基迁移形成2-取代的苯并[ b ]呋喃,或通过a形成3-取代的苯并[ b ]呋喃。直接环化和脱水序列。提出了一种温度依赖性的[1,2]-芳基迁移机制,用于形成2-取代的苯并[ b ]呋喃。