A1 Journal article (refereed)
Chemoselective heterogeneous iridium catalyzed hydrogenation of cinnamalaniline (2021)

Savela, R., Shcherban, N. D., Melander, M. M., Bezverkhyy, I., Simakova, I. L., Långvik, O., Kholkina, E., Schindler, T., Krauβ, A., Honkala, K., Murzin, D. Y., & Leino, R. (2021). Chemoselective heterogeneous iridium catalyzed hydrogenation of cinnamalaniline. Catalysis Science and Technology, 11(4), 1481-1496. https://doi.org/10.1039/D0CY01886D

JYU authors or editors

Melander, Marko
Honkala, Karoliina

Publication details

All authors or editors: Savela, Risto; Shcherban, Nataliya D.; Melander, Marko M.; Bezverkhyy, Igor; Simakova, Irina L.; Långvik, Otto; Kholkina, Ekaterina; Schindler, Tamara; Krauβ, Annabelle; Honkala, Karoliina; et al.

Journal or series: Catalysis Science and Technology

ISSN: 2044-4753

eISSN: 2044-4761

Publication year: 2021

Volume: 11

Issue number: 4

Pages range: 1481-1496

Publisher: Royal Society of Chemistry

Publication country: United Kingdom

Publication language: English

DOI: https://doi.org/10.1039/D0CY01886D

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/74897

Abstract

Selective hydrogenation of unsaturated imines over heterogeneous catalysts is an ecologically feasible and effective way to produce commercially valuable saturated imines and unsaturated amines under mild conditions, avoiding the utilization of toxic halides. The liquid-phase hydrogenation of a model imine, cinnamalaniline, over Ir, Ru, Pd and Au catalysts was studied in polar protic (methanol, 2-propanol), polar aprotic (methyl tert-butyl ether) and non-polar aprotic (toluene) solvents at 40–80 °C under atmospheric hydrogen pressure. Different metal oxides (Al2O3, ZrO2, SiO2) and carbon composites based on carbon nitrides synthesized by pyrolysis of ethylenediamine or melamine modified by KOH, HNO3, NH4Cl or TEOS (including template KIT-6), porous carbon (samples prepared by pyrolysis of sucrose, including template KIT-6) and mesoporous carbon Sibunit were applied to study the effect of the support. Among the tested metals, iridium exhibited the most promising catalytic performance in terms of hydrogenation activity and chemoselectivity towards unsaturated amine. The use of Ir on carbon nitrides (C3N4–NH4Cl, CxNy-KIT-6) and amphoteric metal oxides (ZrO2, Al2O3) in nonpolar aprotic toluene solvent provided the best selectivity towards unsaturated amine by minimizing oligomerization. Computational studies indicate that the selective hydrogenation of the C=N group on Ir results from a favorable cinnamalaniline adsorption geometry at high surface coverage. Comparable heterogeneously catalyzed highly chemoselective hydrogenation of unsaturated imine into unsaturated amine under atmospheric hydrogen pressure and low temperatures has not been reported previously.

Keywords: chemical synthesis; organic compounds; nitrogen compounds; hydrogenation; catalysis; catalysts; platinoids