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首页> 外文期刊>Chemistry: A European journal >First X-ray Structure of a N-Naphthaloyl-Tethered Chiral Dirhodium(II) Complex: Structural Basis for Tether Substitution Improving Asymmetric Control in Olefin Cyclopropanation
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First X-ray Structure of a N-Naphthaloyl-Tethered Chiral Dirhodium(II) Complex: Structural Basis for Tether Substitution Improving Asymmetric Control in Olefin Cyclopropanation

机译：N萘甲酸酯系手性Dirhodium（II）配合物的第一个X射线结构：系链取代的结构基础提高了烯烃环丙烷化中的不对称控制。

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摘要

The transition-metal-catalyzed cyclopropanation of olefins with diazoesters occupies a prominent position in the field of asymmetric catalysis. This stems not only from being the reaction in which asymmetric catalysis by transition metals was first demonstrated, but also because of its prevalence in natural-product-based and synthetic drugs.[1] Once this principle was demonstrated, highly selective catalysts were developed, mainly based on CuI and RhII associated with appropriate chiral nonracemic ligands.[2] The intermediacy of metallocarbenes in transition-metal-catalyzed decomposition of diazo precursors is firmly established.[1, 2] In the case of the paddle-wheel dirhodium(II) catalysts based on amino acid derived ligands, enantioselectivity arises from the concerted control of the carbene-transfer step (metal to olefin) offered by the chiral ligand set flanking an axial coordination site of the dirhodium complex. A recent report discussed the role of the chiral crown cavity of the well-known Hashimoto catalyst [Rh2{(S)-pttl}4] (pttl=N-phthaloyl-(S)-tert- eucinate) formed by the four N-phthaloyl units in this regard, Scheme 1.[3a]
机译：具有重氮酯的过渡金属催化的烯烃的环丙烷化在不对称催化领域中占有重要地位。这不仅源于首先证明过渡金属不对称催化的反应，还源于其在天然产物和合成药物中的普遍使用。[1]一旦证明了这一原理，就可以开发出高度选择性的催化剂，主要基于与适当的手性非外消旋配体相关的CuI和RhII。[2]重金属在重金属催化的重氮前体分解中的金属间化合物的中间体牢固建立。[1，2]在基于氨基酸衍生配体的桨轮（II）催化剂的情况下，对映异构体的选择性是由对苯丙氨酸的一致控制而产生的。由手性配体组提供的碳烯转移步骤（从金属到烯烃）位于侧键配合物的轴向配位位点两侧。最近的一份报告讨论了由四个N-形成的桥本催化剂[Rh2 {（S）-pttl} 4]（pttl = N-邻苯二甲酰基-（S）-叔丁氨酸）的手性冠腔的作用。在这方面，方案1的邻苯二甲酰基单元。[3a]

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