Meta halogenation of 1,3-disubstituted arenes via iridium-catalyzed arene borylation
Meta halogenation of 1,3-disubstituted arenes via iridium-catalyzed arene borylation
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DOI：
10.1021/ja076498n
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发表时间：
2007-12-19
影响因子：
15
通讯作者：
Hartwig, John F.
中科院分区：
文献类型：
--
作者：
Murphy, Jaclyn M.;Liao, Xuebin;Hartwig, John F.
本文报道了铱催化芳烃硼化反应，使1，3-二取代芳烃发生间位卤化反应，生成3，5-二取代芳基溴和氯。铱催化的芳烃与B（2）pin（2）的硼基化反应，随后硼酸酯与溴化铜（II）或氯化铜（II）反应，将芳基硼酸酯转化为相应的芳基卤。各种含烷氧基、烷基、卤素、腈、酯、酰胺和新戊酰基的芳烃和TIPS保护的醇被转化为相应的3，5-二取代芳基溴化物和氯化物，产率在46%至85%之间。此外，2，6-二取代和3-取代吡啶分别转化为4-卤代和5-卤代吡啶。该方法的实用性被证明是由尼古丁的阿替尼克林在三个步骤中的总收率为61%，使用尼古丁的间溴化作为第一步的正式转换。
We report the meta halogenation of 1,3-disubstituted arenes to form 3,5-disubstituted aryl bromides and chlorides by using iridium-catalyzed arene borylation chemistry. Iridium-catalyzed borylation of arenes with B(2)pin(2), followed by reaction of the boronic ester with copper(II) bromide or chloride converts arylboronic esters to the corresponding aryl halides. A variety of arenes containing alkoxy, alkyl, halogen, nitrile, ester, amide, and pivaloyl and TIPS-protected alcohols were converted to the corresponding 3,5-disubstituted aryl bromides and chlorides in yields ranging from 46% to 85%. In addition, 2,6-disubstituted and 3-substituted pyridines were converted to the 4-halo and 5-halopyridines, respectively. The utility of this methodology was demonstrated by the formal conversion of nicotine to Altinicline in three steps with an overall yield of 61% using meta bromination of nicotine as the first step.