A well-defined low-coordinate β-diketiminatocobalt(II) alkyl complex is reported as an active precatalyst for the selective alkene cyclohydroamination of unprotected primary amines under mild conditions (rt–90 °C). The reaction mechanism has been investigated by deuterium-labeling, kinetics, and stoichiometric experiments and in-depth computational DFT studies. On the basis of these studies, we propose a stepwise noninsertive mechanism that features a rate-determining nucleophilic attack of the amido group of a monomeric cobalt(II) amidoalkene-aminoalkene adduct intermediate to the noncoordinated pendant alkene followed by a rapid proton transfer from the coordinated aminoalkene to the cyclized adduct.

中文翻译：

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定义良好的β-二酮亚胺基钴（II）配合物用于伯胺的烯烃环加氢胺化

据报道，在温和的条件下（rt-90°C），定义明确的低配位β-二酮亚氨基钴（II）烷基络合物可作为未保护的伯胺选择性烯烃环加氢胺化的活性预催化剂。已通过氘标记，动力学和化学计量学实验以及深入的DFT计算研究了该反应机理。在这些研究的基础上，我们提出了一种分步的非插入性机理，其特征在于速率确定单体钴（II）酰胺基烯烃-氨基烯烃加合物中间物的酰胺基团向非配位侧链烯烃的亲核进攻，随后质子迅速从配位的氨基烯烃与环化加合物。