Our adventure in carbocatalysis was initiated in studies of heterogeneous gold catalysis on activated carbon surface

Initially, we developed heterogeneous gold catalysis in collaboration with Dr. Lopez Sanchez group in Liverpool. Cycloisomerization of 2-Alkynylanilines to Indoles Catalyzed by Carbon-Supported Gold Nanoparticles and Subsequent Homocoupling to 3,3′-Biindoles, J. Burea-Buceta et al. Angew. Chem., Int. Ed. 2013, 52, 11835. (https://doi.org/10.1002/anie.201305579)

The groundbreaking finding in the study was that oxidized (HNO3 treated) activated carbon (oAC) could mediate oxidative dehydrogenative (ODH) homocoupling of indoles i.e. promote C(sp2)-H C(sp2)-C(sp2) coupling.

Later on, we optimized the AC oxidation degree, characterized the carbon materials, demonstrated a broader applicability and proposed a quinoidic mechanism of carbocatalysis by Carbocatalysed Oxidative Csp2-Csp2 Homocouplings of Benzo-Fused Heterocycles T. Wirtanen et al Adv. Synth. Catal. 2015, 357, 3718. (https://doi.org/10.1002/adsc.201500664)

After a while, when utilizing the carbocatalysis in the synthesis heteroaryl fused cyclooctatetraenes, we were able to make a mechanistic update: Divergent Carbocatalytic Routes in Oxidative Coupling of Benzofused Heteroaryl Dimers, D. Casadio et al., Chem. Eur. J. 2021, 27, 5283. (https://doi.org/10.1002/chem.202005433)

We have also shown that oxidative treated carbon nanotubes offers tensile catalytic material for catalysis analogous couplings for electron rich aryls. “Carbocatalytic Oxidative Dehydrogenative Couplings of (Hetero)Aryls by Oxidized Multi-Walled Carbon Nanotubes in Liquid Phase” T. Wirtanen et al. Chem. Eur. J., 2019, 25, 12288. (https://doi.org/10.1002/chem.201903054)

Inspired by classic gas-phase carbocatalytic OHD reactions enabling ethylbenzene dehydrogenation to styrene, we became interested whether liquid phase ODH carbocatalysis would allow aromatizations of heteroaryl substituted cyclohexenes. Air oxidized activated carbon catalyst for aerobic oxidative aromatizations of N-heterocycles, L. Enders et al. Catal. Sci. Technol., 2021, 11, 5962. (https://doi.org/10.1039/D1CY00878A)

We also found out that oAC is capable to meditae Carbocatalytic Cascade Synthesis of Polysubstituted Quinolines from Aldehydes and 2-Vinyl Anilines, M. Mäkelä et al. Adv. Synth.Catal. 2021, 363, 377 (https://doi.org/10.1002/adsc.202100711)

Our collaboration with prof. Yongdan Li group, Aalto, in BioCat project has produced an accepted manuscript “A metal-free carbon catalyst for oxidative dehydrogenation of aryl cyclohexenes to produce biaryl compounds“, PNAS

Beyond above, we are intensively developing new carbocatalytic transformations and looking for new ways to prepare efficient catalytically active carbon materials. We have freshly reviewed the recent developments in the field “Carbon Materials as Catalytic Tools for Oxidative dehydrogenations and Couplings in Liquid Phase” A. Lenarda, Synthesis 2023, 55, 45. (DOI: 10.1055/a-1931-0749)

We have also freshly demonstrated that lignin can be carbonized for an effective ODH-catalyst with ACS Catalysis publication “Chemically activated Spruce Organosolv Lignin as Carbocatalyst for Heterogeneous Oxidative Dehydrogenations in Liquid Phase ” (DOI: 10.1021/acscatal.3c02735)