Tuning the electronic properties of tetradentate iron-NHC complexes: Towards stable and selective epoxidation catalysts
作者:Marco A. Bernd、Florian Dyckhoff、Benjamin J. Hofmann、Alexander D. Böth、Jonas F. Schlagintweit、Jens Oberkofler、Robert M. Reich、Fritz E. Kühn
DOI:10.1016/j.jcat.2020.08.037
日期:2020.11
Two sets of bio-inspired non-heme iron complexes, each comprising of an FeII and FeIII species, bearing 16-membered macrocyclic tetradentate N–heterocyclic carbene ligands are reported. The complexes exhibit trans labile coordination sites, are characterized by means of NMR, ESI-MS, elemental analysis, SC-XRD and cyclic voltammetry and assessed as olefin epoxidation (pre–)catalysts applying H2O2 as
据报道,有两组生物启发的非血红素铁配合物,每一个都由一个Fe II和Fe III物种组成,带有16元大环四齿N-杂环卡宾配体。配合物表现出反式不稳定配位点,其特点是NMR,ESI-MS,元素分析,SC-XRD和循环伏安法的装置和评定为烯烃环氧化(预)催化剂施加ħ 2 ö 2作为氧化剂。Sc(OTf)3和AcOH分别被评价为路易斯和布朗斯台德酸性添加剂,从而在催化性能方面产生了部分明显的改善。特此,复数2b具有高稳定性(在20°C下TON = 1,000),高温耐受性以及在末端烯烃和官能化烯烃更具挑战性的环氧化方面取得的进展。此外,进行了深入的DFT计算,以将催化剂的结构和电子特征与催化结果联系起来。