Transition-metal-catalyzed cross-coupling reactions have been well-established as indispensable tools in modern organic synthesis. One of the major research goals in cross-coupling area is expanding the scope of the coupling partners. In the past decade, diazo compounds (or their precursors N-tosylhydrazones) have emerged as nucleophilic cross-coupling partners in C–C single bond or C═C double bond formations in transition-metal-catalyzed reactions. This type of coupling reaction involves the following general steps. First, the organometallic species is generated by various processes, including oxidative addition, transmetalation, cyclization, C–C bond cleavage, and C–H bond activation. Subsequently, the organometallic species reacts with the diazo substrate to generate metal carbene intermediate, which undergoes rapid migratory insertion to form a C–C bond. The new organometallic species generated from migratory insertion may undergo various transformations. This type of carbene-based coupling has proven to be general: various transition metals including Pd, Cu, Rh, Ni, Co, and Ir are effective catalysts; the scope of the reaction has also been extended to substrates other than diazo compounds; and various cascade processes have also been devised based on the carbene migratory insertion. This review will summarize the achievements made in this field since 2001.

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碳迁移迁移插入的过渡金属催化交叉偶联

过渡金属催化的交叉偶联反应已被公认是现代有机合成中必不可少的工具。交叉耦合领域的主要研究目标之一是扩大耦合伙伴的范围。在过去的十年中，重氮化合物（或其前体N-tosylhydrazones）在过渡金属催化的反应中以C–C单键或C═C双键形成亲核交叉偶联伙伴。这种偶联反应涉及以下一般步骤。首先，有机金属物质是通过各种过程产生的，包括氧化加成，金属转移，环化，CC键断裂和CH键活化。随后，有机金属物质与重氮底物反应生成金属卡宾中间体，该中间体经过快速迁移插入形成C–C键。由迁移插入产生的新的有机金属物质可能经历各种转化。这种基于卡宾的偶联已被证明是普遍的：包括Pd，Cu，Rh，Ni，Co和Ir在内的各种过渡金属是有效的催化剂。反应范围也已扩大到重氮化合物以外的其他底物。基于卡宾迁移插入，还设计了各种级联方法。这篇综述将总结自2001年以来在该领域取得的成就。