The synthesis of trimethylamine (TMA) through a multicomponent combination of ammonia with carbon dioxide and molecular hydrogen by using a homogeneous ruthenium catalyst was explored. The use of [Ru(triphos)(tmm)] [triphos: 1,1,1-tris(diphenylphosphinomethyl)ethane, tmm: trimethylene methane] together with aluminum trifluoromethanesulfonate as a co-catalyst resulted in high ammonia conversion and excellent selectivity for TMA in organic solvents. Aqueous solutions of ammonium chloride were methylated almost quantitatively to the corresponding hydrochloride salt (i.e., TMA⋅HCl) in a biphasic solvent system by using the same Ru complex without the need for any co-catalyst.

The development of a tailored tridentate ligand enabled the synthesis of a molecular ruthenium-triphos catalyst, eliminating dimerization as the major deactivation pathway. The novel catalyst design showed strongly increased performance and facilitated the hydrogenation of highly challenging lactam substrates with unprecedented activity and selectivity.

The development of a tailored tridentate ligand enabled the synthesis of a molecular ruthenium-triphos catalyst, eliminating dimerization as the major deactivation pathway. The novel catalyst design showed strongly increased performance and facilitated the hydrogenation of highly challenging lactam substrates with unprecedented activity and selectivity.

Dieser Aufsatz diskutiert die Chancen und Herausforderungen für die Nutzung der Kombination aus Kohlendioxid und Wasserstoff als C₁-Synthon in katalytischen Reaktionen und Prozessen. Die Transformationen werden anhand des Reduktionsgrades und der Bindungsknüpfung geordnet, wobei die chemische Wertschöpfungskette von großvolumigen Grundchemikalien bis hin zu komplexen Molekülen mit biologischer Wirkung abgedeckt wird. Die chemischen Transformationen erlauben zum einen die Speicherung und Nutzung von erneuerbaren Energien in stofflichen Produkten und bieten gleichzeitig Möglichkeiten für ressourcenschonende und umweltfreundliche Herstellungsprozesse. Interdisziplinäre Grundlagenforschung von Chemikern und Ingenieuren kann so zu nachhaltigen Technologien an der Schnittstelle von Energie und Chemie beitragen. Der Aufsatz lädt den Leser dazu ein, das “katalytische Schachbrett” der Nutzung von CO₂ und H₂ kennenzulernen und vielleicht selbst einige Partien darauf zu beginnen.

The present Review highlights the challenges and opportunities when using the combination CO₂/H₂ as a C₁ synthon in catalytic reactions and processes. The transformations are classified according to the reduction level and the bond-forming processes, covering the value chain from high volume basic chemicals to complex molecules, including biologically active substances. Whereas some of these concepts can facilitate the transition of the energy system by harvesting renewable energy into chemical products, others provide options to reduce the environmental impact of chemical production already in today's petrochemical-based industry. Interdisciplinary fundamental research from chemists and chemical engineers can make important contributions to sustainable development at the interface of the energetic and chemical value chain. The present Review invites the reader to enjoy this exciting area of “catalytic chess” and maybe even to start playing some games in her or his laboratory.

Ruthenium–triphos complexes exhibited unprecedented catalytic activity and selectivity in the redox-neutral CC bond cleavage of the β-O-4 lignin linkage of 1,3-dilignol model compounds. A mechanistic pathway involving a dehydrogenation-initiated retro-aldol reaction for the CC bond cleavage was proposed in line with experimental data and DFT calculations.

Ruthenium–triphos complexes exhibited unprecedented catalytic activity and selectivity in the redox-neutral CC bond cleavage of the β-O-4 lignin linkage of 1,3-dilignol model compounds. A mechanistic pathway involving a dehydrogenation-initiated retro-aldol reaction for the CC bond cleavage was proposed in line with experimental data and DFT calculations.

The use of the well-defined [Ru(triphos)(tmm)] catalyst, CO₂ as C₁ source, and H₂ as reducing agent enabled the reductive methylation of isolated imines, as well as the direct coupling of amines with aldehydes and the subsequent reductive methylation of the in situ formed imines. The method, which afforded the corresponding N-methyl amines in very good to excellent yields, was also used for the preparation of the antifungal agent butenafine in one step with no apparent waste, thus increasing the atom efficiency of its synthesis.

The use of the well-defined [Ru(triphos)(tmm)] catalyst, CO₂ as C₁ source, and H₂ as reducing agent enabled the reductive methylation of isolated imines, as well as the direct coupling of amines with aldehydes and the subsequent reductive methylation of the in situ formed imines. The method, which afforded the corresponding N-methyl amines in very good to excellent yields, was also used for the preparation of the antifungal agent butenafine in one step with no apparent waste, thus increasing the atom efficiency of its synthesis.

para-Hydrogen induced polarization (PHIP) NMR spectroscopy emerges as an efficient and robust method for on-line monitoring of gas-phase hydrogenation reactions. Here we report detailed investigations of supported ionic liquid phase (SILP) catalysts in a continuous gas-phase hydrogenation of propene with PHIP NMR spectroscopy. A relocation of the rhodium complex in the thin layer of ionic liquid in the SILP catalyst at the initial stage of the propene hydrogenation is demonstrated. PHIP NMR spectroscopy can provide profound insight into the evolution of SILP catalysts during hydrogenation reactions.