Bagh Bidraha, Broere Daniël L J, Sinha Vivek, Kuijpers Petrus F, van Leest Nicolaas P, de Bruin Bas, Demeshko Serhiy, Siegler Maxime A, van der Vlugt Jarl Ivar
Homogeneous, Bioinspired and Supramolecular Catalysis, van't Hoff Institute for Molecular Sciences, University of Amsterdam , Science Park 904, 1098 XH, Amsterdam, The Netherlands.
Institüt für Anorganische Chemie, Georg-August-Universität Göttingen , Tammannstraße 4, 37077 Göttingen, Germany.
J Am Chem Soc. 2017 Apr 12;139(14):5117-5124. doi: 10.1021/jacs.7b00270. Epub 2017 Mar 28.
Coordination of FeCl to the redox-active pyridine-aminophenol ligand NNO in the presence of base and under aerobic conditions generates FeCl(NNO) (1), featuring high-spin Fe and an NNO radical ligand. The complex has an overall S = 2 spin state, as deduced from experimental and computational data. The ligand-centered radical couples antiferromagnetically with the Fe center. Readily available, well-defined, and air-stable 1 catalyzes the challenging intramolecular direct C(sp)-H amination of unactivated organic azides to generate a range of saturated N-heterocycles with the highest turnover number (TON) (1 mol% of 1, 12 h, TON = 62; 0.1 mol% of 1, 7 days, TON = 620) reported to date. The catalyst is easily recycled without noticeable loss of catalytic activity. A detailed kinetic study for C(sp)-H amination of 1-azido-4-phenylbutane (S) revealed zero order in the azide substrate and first order in both the catalyst and BocO. A cationic iron complex, generated from the neutral precatalyst upon reaction with BocO, is proposed as the catalytically active species.
在碱存在和有氧条件下，FeCl与氧化还原活性吡啶 - 氨基酚配体NNO配位生成FeCl(NNO)（1），其具有高自旋铁和NNO自由基配体。根据实验和计算数据推断，该配合物具有整体S = 2的自旋态。配体中心自由基与铁中心发生反铁磁耦合。易于获得、结构明确且空气稳定的1催化未活化有机叠氮化物具有挑战性的分子内直接C(sp)-H胺化反应，以生成一系列饱和N-杂环化合物，其周转数（TON）是迄今报道的最高值（1的1 mol%，12小时，TON = 62；1的0.1 mol%，7天，TON = 620）。该催化剂易于循环使用，且催化活性无明显损失。对1-叠氮基-4-苯基丁烷（S）的C(sp)-H胺化反应进行的详细动力学研究表明，叠氮化物底物为零级反应，催化剂和BocO均为一级反应。由中性前体催化剂与BocO反应生成的阳离子铁配合物被认为是催化活性物种。
