Maity Arnab K, Kalb Annah E, Zeller Matthias, Uyeda Christopher
Department of Chemistry, Purdue University, 560 Oval Dr., West Lafayette, IN, 47907, USA.
Angew Chem Int Ed Engl. 2021 Jan 25;60(4):1897-1902. doi: 10.1002/anie.202011602. Epub 2020 Nov 23.
(NDI)Ni catalysts (NDI=naphthyridine-diimine) promote cyclopropanation reactions of 1,3-dienes using (Me Si)CHN . Mechanistic studies reveal that a metal carbene intermediate is not part of the catalytic cycle. The (NDI)Ni (CHSiMe ) complex was independently synthesized and found to be unreactive toward dienes. Based on DFT models, we propose an alternative mechanism that begins with a Ni -mediated coupling of (Me Si)CHN and the diene. N extrusion followed by radical C-C bond formation generates the cyclopropane product. This model reproduces the experimentally observed regioselectivity and diastereoselectivity of the reaction.
（NDI）镍催化剂（NDI = 萘啶二亚胺）使用（Me₃Si）₂CHN促进1,3 - 二烯的环丙烷化反应。机理研究表明，金属卡宾中间体不是催化循环的一部分。（NDI）Ni（CHSiMe₃）₂配合物已独立合成，发现其对二烯无反应活性。基于密度泛函理论（DFT）模型，我们提出了一种替代机理，该机理始于镍介导的（Me₃Si）₂CHN与二烯的偶联。随后通过氮挤出和自由基碳 - 碳键形成生成环丙烷产物。该模型再现了实验观察到的反应区域选择性和非对映选择性。
