We are interested in improving the catalytic performance of catalysts in the functionalization of organic molecules and the synthesis of polymers. Below are given a few recent examples from our research work:

Gold-catalyzed Alkyne Functionalization.

The virtually quantitative, room temperature hydration of various terminal and internal alkynes in methanol/water requires between 0.01–0.05 mol% of [AuCl(NHC)] activated with 1.5 equiv. of silver triflate and 45 equiv. of triflic acid (both relative to gold complex) with ton of up to 300.000. Iptycenyl-substituted NHC ligands play the key role and the most efficient NHC ligand is characterized by a hemispherical shape formed by two N-pentiptycenyl substituents.

Bispentiptycenyl-N-Heterocyclic Carbene (NHC) Gold Complexes: Highly Active Catalysts for the Room Temperature Hydration of Alkynes, M. Heidrich, M. Bergmann, D. Müller-Borges, H. Plenio, Adv. Synth. Catal. 2018, 360, 3572-3578.

Nickel-catalyzed Ethene Polymerization.

Ni2+ coordinated within a bowl-shaped diimine ligand with two pentiptycenyl-substituents [(diimine)NiBr2] displays excellent activity for the polymerization of ethene (7 atm) with activities of up to 34 × 103 kg(mol Ni)−1 h−1 following activation with Et2AlCl. The resulting polymer is characterized by high molecular weights (Mn = 150 × 103 g·mol−1), low branching (12/1000 C), and a high melting point (Tm = 133 °C). The polymerization of ethene with polar comonomers leads to the formation of the respective polar polymers with very efficient incorporation of comonomer. The activity of the catalyst critically depends on the molar ratio of Et2AlCl activator and the polar functional group.

Bispentiptycenyl-Diimine-Nickel Complexes for Ethene Polymerization and Copolymerization with Polar Monomers, Y. Kanai, S. Foro, H. Plenio, Organometallics 2019, 38, 544-551.

Ruthenium-catalyzed alt-ROMP.

A Grubbs-Hoveyda type catalyst with a N-pentiptycenyl, N-cyclohexyl-NHC ligand provides poly(nbe-alt-coe) with an excellent degree of alternation while lacking significant activity in the homopolymerization of cyclooctene.

Alternating Ring-Opening Metathesis Polymerization by Grubbs-Type Catalysts with N-Pentiptycenyl, N-Alkyl-NHC Ligands, R. Vasiuta, A. Stockert, H. Plenio, Chem. Commun. 2018, 54, 1706-1709.