Cu-α-diimine Compounds Encapsulated in Porous Materials as Catalysts for Electrophilic Amination of Aromatic C–H Bonds

Lisa Van Emelen, Vincent Lemmens, Carlos Marquez, Sam Van Minnebruggen, Oleg A. Usoltsev, Aram L. Bugaev, Kwinten Janssens, Ka Yan Cheung, Niels Van Velthoven, Dirk E. De Vos

Research output: Contribution to journalArticlepeer-review


Electrophilic amination has emerged as a more environmentally benign approach to construct arene C–N bonds. However, heterogeneous catalysts remain largely unexplored in this area, even though their use could facilitate product purification and catalyst recovery. Here we investigate strategies to heterogenize a Cu(2,2′-bipyridine) catalyst for the amination of arenes lacking a directing group with hydroxylamine-O-sulfonic acid (HOSA). Besides immobilization of Cu on a metal–organic framework (MOF) or covalent organic framework (COF) with embedded 2,2′-bipyridines, a ship-in-a-bottle approach was followed in which the Cu complex is encapsulated in the pores of a zeolite. Recyclability and hot centrifugation tests show that zeolite Beta-entrapped CuII(2,2′-bipyridine) is superior in terms of stability. With N-methylmorpholine as a weakly coordinating, weak base, simple arenes, such as mesitylene, could be aminated with yields up to 59%, corresponding to a catalyst TON of 24. The zeolite could be used in three consecutive runs without a decrease in activity. Characterization of the catalyst by EPR and XAS showed that the active catalytic complex consisted of a site-isolated CuII species with one 2,2′-bipyridine ligand.
Original languageEnglish (US)
JournalACS Applied Materials & Interfaces
StatePublished - Nov 9 2022
Externally publishedYes

Bibliographical note

KAUST Repository Item: Exported on 2022-11-14
Acknowledged KAUST grant number(s): OSR-2018-CRG7-3741.2
Acknowledgements: L.V.E. and S.V.M. thank the Fonds Wetenschappelijk Onderzoek (FWO) for funding (scholarship 1161019 N and 1SA0921N, respectively) and Dirk Dom for assistance with the EPR measurements. V.L. and D.E.D.V. acknowledge the KAUST-CRG program (OSR-2018-CRG7-3741.2). C.M. thanks VLAIO (Flemish Agency for Innovation and Entrepreneurship) via the Flemish spearhead cluster Catalisti for financial support (Moonshot cluster SBO project PREFER, HBC.2020.2609 ″The plastics refinery: no more waste″). K.J. and D.E.D.V. thank FWO for project funding (grant G0F2320N). We are indebted to Anna Pnevskaya, Viktor Shapovalov, and Olga Safonova for their help with XAS measurements. O.A.U. acknowledges the Strategic Academic Leadership Program of the Southern Federal University (″Priority 2030″) for experimental XAS investigation. Theoretical interpretation of Cu K-edge XANES was supported by grant MK-5853.2021.1.2 (agreement no. 075-15-2021-499).
This publication acknowledges KAUST support, but has no KAUST affiliated authors.

ASJC Scopus subject areas

  • Materials Science(all)


Dive into the research topics of 'Cu-α-diimine Compounds Encapsulated in Porous Materials as Catalysts for Electrophilic Amination of Aromatic C–H Bonds'. Together they form a unique fingerprint.

Cite this