Comparative Study on the Reactivity of 6-Haloimidazo[1,2-a]pyridine Derivatives towardsNegishi- andStille-Coupling Reactions
作者:Maud Hervet、Isabelle Théry、Alain Gueiffier、Cécile Enguehard-Gueiffier
DOI:10.1002/hlca.200390290
日期:2003.10
Suzuki-cross-coupling reaction of 6-haloimidazo[1,2-a]pyridines is dependent on the availability of the (hetero)arylboronic acids. Thus, with the aim to develop expanded applications of (hetero)arylations of imidazo[1,2-a]pyridines, we investigated the Negishi- and Stille-cross-coupling reactions at the 6-position. Remarkably, attempts to apply the Negishi-cross-coupling conditions to the organozinc derivative prepared
6-卤代咪唑并[1,2- a ]吡啶的铃木交叉偶联反应的范围取决于(杂)芳基硼酸的可用性。因此,具有的目标是发展扩大的咪唑并(杂)芳基化的应用[1,2一]吡啶,我们研究了根岸-和的Stille -Cross偶联反应在6-位。值得注意的是,尝试将Negishi交叉偶联条件应用于由6-卤代咪唑并[1,2- a ]吡啶经锂锌交换制得的有机锌衍生物,导致5-苯基化合物3的产率为54%,而不是所需的6 -苯基异构体(方案1)。相反,在Stille条件下,将各种可商购的卤化的五或六元环杂环有效地偶联至6-(三烷基锡烷基)咪唑并[1,2- a ]吡啶(表2)。