Synthesis of Benzo[b]thiophenes by Cyclization of Arylketene Dithioacetal Monoxides under Pummerer-like Conditions
摘要:
Treatment of arylketene bis(methylthio)acetal monoxide with trifluoromethanesulfonic anhydride leads to ring-closure to afford 2-methylthiobenzo-[b]thiophene in high yield. The reaction is useful for synthesizing multisubstituted benzo[b]thiophenes.
A combination of a palladium–NHC catalyst and potassium hexamethyldisilazide enables the amination of aryl sulfides with anilines to afford a wide variety of diarylamines. The reaction conditions are versatile enough for the reaction of even bulky ortho‐substituted aryl sulfides. This amination can be applied to the modular synthesis of N‐aryl carbazoles from the corresponding ortho‐bromothioanisoles
Palladium-Catalyzed Zinc-Amide-Mediated CH Arylation of Fluoroarenes and Heteroarenes with Aryl Sulfides
作者:Shinya Otsuka、Hideki Yorimitsu、Atsuhiro Osuka
DOI:10.1002/chem.201502101
日期:2015.10.12
heteroarenes with aryl sulfides proceeds smoothly with the aid of a palladium–N‐heterocyclic carbene catalyst. A bulky zinc amide, TMPZnCl⋅LiCl, plays a key role as an effective base to generate the corresponding arylzinc species in situ. This arylation protocol is practically much easier to perform than our previous method, which necessitates preparation of the arylzincreagents in advance from the corresponding
Ç polyfluoroarenes和杂芳烃的与芳基硫化物ħ芳基化用钯- N-杂环卡宾催化剂的帮助下顺利进行。甲笨重锌酰胺,TMPZnCl ⋅的LiCl,起着以原位产生相应的芳基锌物种的有效碱关键作用。该芳基化方案实际上比我们以前的方法更容易执行,后者需要从相应的芳基卤化物预先制备芳基锌试剂。通过硫特异性反应(如S N Ar磺酰化反应和扩展的Pummerer反应)制备的芳基硫化物会经历这种直接芳基化,从而提供有趣的转化,而这些转化是传统的基于卤素的有机合成难以实现的。
Synthesis of Benzo[<i>b</i>]thiophenes by Cyclization of Arylketene Dithioacetal Monoxides under Pummerer-like Conditions
Treatment of arylketene bis(methylthio)acetal monoxide with trifluoromethanesulfonic anhydride leads to ring-closure to afford 2-methylthiobenzo-[b]thiophene in high yield. The reaction is useful for synthesizing multisubstituted benzo[b]thiophenes.