Chiral transition metal catalysts represent a powerful and economic tool for implementing stereocenters in organic synthesis, with the metal center providing a strong chemical activation upon its interaction with substrates or reagents, while the overall chirality of the metal complex achieves the desired stereoselectivity. Often, the overall chiral topology of the metal complex implements a stereogenic metal center, which is then involved in the origin of the asymmetric induction. This review provides a comprehensive survey of reported chiral transition metal catalysts in which the metal formally constitutes a stereocenter. A stereogenic metal center goes along with an overall chiral topology of the metal complex, regardless of whether the ligands are chiral or achiral. Implications for the catalyst design and mechanism of asymmetric induction are discussed for half-sandwich, tetracoordinated, pentacoordinated, and hexacoordinated chiral transition metal complexes containing a stereogenic metal center. The review distinguishes between chiral metal catalysts originating from the coordination to chiral ligands and those which are solely composed of optically inactive ligands (achiral or rapidly interconverting enantiomers) prior to complexation (dubbed “chiral-at-metal” catalysts).

中文翻译：

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不对称过渡金属催化中的金属立构性

手性过渡金属催化剂代表了在有机合成中实现立体中心的强大且经济的工具，金属中心在与底物或试剂相互作用时提供强烈的化学活化，而金属配合物的整体手性实现了所需的立体选择性。通常，金属配合物的整体手性拓扑结构实现了立体金属中心，然后参与不对称感应的起源。本综述对已报道的手性过渡金属催化剂进行了全面调查，其中金属正式构成立体中心。无论配体是手性还是非手性，手性金属中心都伴随着金属配合物的整体手性拓扑结构。讨论了包含立体异构金属中心的半夹心、四配位、五配位和六配位手性过渡金属配合物的催化剂设计和不对称诱导机制的意义。该综述区分了源自与手性配体配位的手性金属催化剂和那些在络合之前仅由光学非活性配体（非手性或快速互变对映体）组成的手性金属催化剂（称为“金属手性”催化剂）。