Amidocuprates for Directed ortho Cupration : Structural Study, Mechanistic Investigation, and Chemical Requirements
Amidocuprates for Directed ortho Cupration : Structural Study, Mechanistic Investigation, and Chemical Requirements
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用于定向邻位铜化的酰胺铜酸盐：结构研究、机理研究和化学要求
DOI：
10.1002/anie.201204923
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Shinsuke Komagawa
中科院分区：
文献类型：
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作者：
Koji Yamamoto;Hayato Tsurugi Kazushi Mashima;Shinsuke Komagawa
有机铜（I）配合物是工业和研究化学中非常有价值的试剂。[1]在过去的几十年里，带有炔基、[2a，B]氰基、[2c，d]苯硫基、[2 e]和膦基[2f，g]的杂配位有机铜化合物在有机合成中占据了重要的地位。有机酰胺铜酸酯在有机转化中，特别是在立体选择性合成中也是一类重要的混配铜酸酯。[3]在这种情况下，我们最近提出了新的用途的amidocuprates，TMP-Cu-ates（[RCu（TMP）（CN）Li]; R=烷基，苯基，和TMP; TMP= 2，2，6，6-四甲基哌啶），这促进了高化学选择性，定向邻铜化的多官能化的芳香族化合物在温和的条件下。芳基铜酸酯中间体不仅可以用于捕获亲电体，而且可以用于氧化配体偶联以与烷基/芳基形成新的C12 C键或引入羟基（方案1）。[4-6]有机铜（I）化合物主要有两种结构类型：Gilman型和Lipshutz型。[7]在每一个中的基本二有机铜（I）酸盐单元采用线性[R-Cu-R]排列。已知吉尔曼型物种表现出同源二聚体结构（图式2a）。理论预测[8]的头-尾二聚的杂配铜酸盐的偏好已被证实的结构[MesCu（NBn 2）Li]（Mes= mesityl，Bn= benzyl）[9]，虽然单体的形成已记录在存在的刘易斯碱。[10]相比之下，Lipshutz型试剂表现出异质聚集体结构（方案2 B）。[2d Lipshutz型铜酸盐（[RCuR'Li· LiCN]）的反应活性通常高于相应的Gilman型试剂（[RCuR'Li]）。[12]为了阐明什么类型的铜酸盐参与定向ortho cupration，我们进行了详细的机械调查，包括X射线分析和计算研究。这导致了单体吉尔曼型结构（方案2c）的出现，这是一种先前已经揭示的相关结构[5]，作为定向去质子化的前所未有的活性物质。我们研究的起点是分析固态的双（氨基）铜酸盐，以与由CuCN和LiTMP反应形成的产物的已知X射线结构进行比较，即
Organocuprate (I) complexes are immensely valuable reagents for both industrial and research chemistry.[1] During the past few decades, heteroleptic organocuprates bearing alkynyl,[2a, b] cyano,[2c, d] phenylthio,[2e] and phosphino [2f, g] groups have secured an important place in organic synthesis. Organo-amidocuprates also represent an important class of heteroleptic cuprates in organic transformations, especially in stereoselective syntheses.[3] In this context, we have recently proposed new uses for amidocuprates, TMP-Cu-ates ([RCu (TMP)(CN) Li]; R= alkyl, phenyl, and TMP; TMP= 2, 2, 6, 6-tetramethylpiperidido), which promote the highly chemoselective, directed ortho cupration of multifunctionalized aromatic compounds under mild conditions. The aryl cuprate intermediate can be employed not only in the trapping of electrophlies, but also in oxidative ligand coupling to form new CÀC bonds with alkyl/aryl groups or to introduce a hydroxy group (Scheme 1).[4–6] Organocuprate (I) chemistry is dominated by two structure types: the Gilman-type and the Lipshutz-type.[7] The basic diorganocuprate (I) unit in each adopts a linear [R-Cu-R] arrangement. Gilman-type species are known to exhibit homodimeric structures (Scheme2a). Theoretical predictions [8] of a preference for head-to-tail dimerization of heteroleptic cuprates have been confirmed by the structure of [MesCu (NBn2) Li](Mes= mesityl, Bn= benzyl),[9] although monomer formation has been recorded in the presence of a Lewis base.[10] In contrast, Lipshutz-type reagents exhibit heteroaggregate structures(Scheme 2 b).[2d, 11] The reactivity of Lipshutz-type cuprates ([RCuR’Li· LiCN]) is frequently higher than that of the corresponding Gilman-type reagents ([RCuR’Li]).[12] To elucidate what types of cuprates are involved in directed ortho cupration we have performed detailed mechanistic investigations, including X-ray analysis and a computational study. This led to the emergence of a monomeric Gilman-type structure (Scheme 2c), a related structure to which has been previously revealed,[5] as the unprecedented, active species for the directed deprotonation. The starting point of our investigation was the analysis of a bis (amido) cuprate in the solid state to draw comparisons with the known X-ray structure of the product formed from the reaction of CuCN and LiTMP, namely