Efficient cobalt-catalyzed formation of unsymmetrical biaryl compounds and its application in the synthesis of a sartan intermediate
Efficient cobalt-catalyzed formation of unsymmetrical biaryl compounds and its application in the synthesis of a sartan intermediate
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DOI：
10.1002/anie.200704402
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发表时间：
2008-01-01
影响因子：
16.6
通讯作者：
Gosmini, Corinne
中科院分区：
文献类型：
--
作者：
Amatore, Muriel;Gosmini, Corinne
不对称联芳基化合物在有机化学中具有重要意义。联芳基结构基序在各种各样的有机过程中遇到，从超分子化学[1]到天然产物合成。[2]在构建芳基-芳基键的无数方法中，过渡金属介导的反应构成了所使用的主要策略之一。[3]通常，这样的反应涉及有机金属试剂（ArM; M= B，[4] Sn，[5] Si，[6] Zn，[7] Mg，[8] Mn [9]）与芳基卤化物或拟卤化物的偶联。它们都需要制备化学计量的有机金属试剂，并且通常需要存在Ni或Pd络合物作为催化剂。最近，已经表明铁[10]和钴[11]催化剂可以在与有机金属试剂的偶联反应中用作昂贵的贵金属（如钯）或有毒金属（如镍）的替代品[12]。金属催化领域的研究为有机合成提供了几种直接的芳基-芳基键形成转化。催化的直接芳烃C13 H交叉偶联[13]和芳族羧酸酯[14]与芳基卤化物的脱羧偶联可能非常有效;然而，这些方法通常需要使用碱、高温和昂贵的催化剂。其他反应途径包括钯催化的两种芳基卤化物与还原剂的还原偶联。[15]为了偶联两种不同的芳基卤化物，我们以前开发了涉及Ni [16]或Co [17]催化的电化学方法。然而，与芳基溴相比，使用芳基氯的转化效率较低，并且没有观察到与芳基拟卤化物的反应。此外，镍对环境有害，当使用钴催化剂时需要大量的催化剂。由于对钴催化反应的兴趣[18]以及我们在使用新的钴催化直接方法[19]方面的早期成功，
Unsymmetrical biaryl compounds are of considerable interest in organic chemistry. The biaryl structural motif is encountered in a wide variety of organic processes, from supramolecular chemistry [1] to natural products synthesis.[2] Among the innumerable methods for the construction of aryl–aryl bonds, transition-metal-mediated reactions constitute one of the main strategies used.[3] Generally, such reactions involve the coupling of an organometallic reagent (ArM; M= B,[4] Sn,[5] Si,[6] Zn,[7] Mg,[8] Mn [9]) with an aryl halide or pseudohalide. They all require the preparation of a stoichiometric organometallic reagent and typically the presence of a Ni or Pd complex as a catalyst. More recently, it has been shown that iron [10] and cobalt [11] catalysts might be employed as alternatives to expensive precious metals, such as palladium, or toxic metals, such as nickel,[12] in coupling reactions with organometallic reagents. Studies within the realms of metal catalysis have provided several direct aryl–aryl bond-forming transformations for organic synthesis. Catalytic direct arene CÀH cross-coupling [13] and the decarboxylative coupling of aromatic carboxylates [14] with aryl halides can be very efficient; however, these methods often require the use of a base, high temperatures, and expensive catalysts. Other reaction pathways include the palladium-catalyzed reductive coupling of two aryl halides in combination with a reducing agent.[15]In an attempt to couple two different aryl halides, we previously developed electrochemical methods involving either Ni [16] or Co [17] catalysis. However, the transformation is less efficient with aryl chlorides than with aryl bromides, and no reaction was observed with aryl pseudohalides. Moreover, nickel is environmentally hazardous, and a large quantity of the catalyst was required when a cobalt catalyst was used. Motivated by the interest in cobalt-catalyzed reactions [18] and our early success in the use of new cobaltcatalyzed direct procedures [19] as an efficient alternative to