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首页> 外文期刊>Chemistry: A European journal >Catalytic Asymmetric Intramolecular Hydroarylations of w-Aryloxy- and Arylamino-Tethered a,b-Unsaturated Aldehydes
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Catalytic Asymmetric Intramolecular Hydroarylations of w-Aryloxy- and Arylamino-Tethered a,b-Unsaturated Aldehydes

机译：w-芳氧基和芳基氨基连接的a，b-不饱和醛的催化不对称分子内氢芳基化反应

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摘要

Phenols, anilines, and their derivatives are chemicals manufactured in large quantities by modern chemical industries and serve as important feedstocks in the synthesis of pharmaceuticals, agro-, and fine chemicals.[1] The development of direct and catalytic synthetic transformations of these simple substrates to valuable compounds has therefore remained a focal point for extensive research effort in both industrial and academic settings. Historically, these transformations are carried out by FriedelCCrafts reactions with acyl or alkyl halides in the presence of Lewis acids.[2] Over the past 20 years, there has been a considerable effort to achieve direct CH functionalization of these electron-rich arenes by CH activation mediated by transition-metal complexes.[ 3] Among them, direct intramolecular hydroarylation represents one of the most powerful transformations for the rapid construction of fused aromatic heterocycles, a common synthon found in natural products and medicinal agents.[4] Despite advances, increasing the diversity of possible substrates and the stereoselectivity of the reaction remain challenges. While a variety of protocols have been described for the intramolecular hydroarylation of the more electron-rich indoles and pyrroles,[5] to our knowledge, only a handful of examples are known for the analogous phenoland aniline-derived reactants.[6] In particular, there are only a couple of examples known to date on the enantioselective intramolecular hydroarylation of benzene derivatives with reasonable enantioselectivity.[6a, b] For instance, Bergman, Ellman, and co-workers developed an intramolecular orthoalkylation of meta-isobutenyl-substituted aromatic imines catalyzed by a chiral rhodium complex, for which 22C 90% ee was observed.[6a, b] This methodology has been limited to specific substrate classes, and the olefin isomerization in the substrate would be problematic in the presence of metal complexes.[6d] Thus, efficient catalytic systems for asymmetric intramolecular hydroarylation are highly desirable.
机译：苯酚，苯胺及其衍生物是现代化学工业大量生产的化学品，在合成药物，农业和精细化学品中是重要的原料。[1]这些简单的底物直接和催化合成转化为有价值的化合物的开发因此仍然是工业和学术环境中广泛研究工作的重点。从历史上看，这些转化是通过在路易斯酸存在下与酰基或烷基卤化物进行FriedelCCrafts反应来进行的。[2]在过去的20年中，人们进行了相当大的努力，以通过过渡金属络合物介导的CH活化来实现这些富电子芳烃的直接CH功能化。[3]其中，分子内直接氢芳基化是最强大的转化方法之一。融合芳香杂环的快速构建，这是天然产物和药物中常见的合成子。[4]尽管取得了进步，但是增加可能的底物的多样性和反应的立体选择性仍然是挑战。尽管已经为富电子的吲哚和吡咯的分子内氢芳基化反应描述了多种方案，[5]据我们所知，对于类似的酚和苯胺衍生的反应物，只有少数几个例子是已知的。[6]尤其是，迄今为止，只有几个关于具有合理对映选择性的苯衍生物的对映选择性分子内氢芳基化的例子。[6a，b]例如，Bergman，Ellman和他的同事开发了间异丁烯基手性铑配合物催化的取代芳族亚胺，观察到22C 90％ee。[6a，b]该方法仅限于特定的底物类型，并且在存在金属配合物的情况下底物中的烯烃异构化会成问题[6d]因此，非常需要用于不对称分子内氢芳基化的有效催化体系。

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