Efficient Cu-ZnO/TiO₂ Catalyst for Direct N-Methylation of N-Methylaniline with CO₂ and H₂

ACS Sustainable Chemistry & Engineering, Год журнала: 2025, Номер unknown

Опубликована: Янв. 2, 2025

The preparation of methyl-substituted amines by direct N-methylation with CO2/H2 is an important reaction for CO2 utilization and organic synthesis. However, the design construction effective stable non-noble-metal catalysts this remain challenging. Here, a cheap non-noble-Cu-based catalyst was prepared applied in N-methylaniline H2. 5%Cu-ZnO(3.75%)/TiO2 showed 98.8% yield initial TOF 7.7 h–1 after 24 h under 453 K, 1.5 MPa CO2, 4.5 H2, which superior to 5%Cu/TiO2, 5%Cu/ZnO, reported Cu-based catalysts. Furthermore, can be reused at least four times various excellent selectivity. characterizations experimental results that Cu0 active site, exhibited largest surface amount, thereby contributing catalytic performance. mechanism H2 proposed based on spectroscopic studies, kinetic control experiments. proceeded HCHO N-methylformanilide intermediates, formation from rate-determining step.

Язык: Английский

Ruthenium Complexes with NNN-Pincer Ligands for N-Methylation of Amines Using Methanol

Inorganic Chemistry, Год журнала: 2024, Номер 63(25), С. 11821 - 11831

Опубликована: Июнь 7, 2024

A series of ruthenium complexes (Ru1–Ru4) bearing new NNN-pincer ligands were synthesized in 58–78% yields. All the are air and moisture stable characterized by IR, NMR, high-resolution mass spectra (HRMS). In addition, structures Ru1–Ru3 confirmed X-ray crystallographic analysis. These Ru(II) exhibited high catalytic efficiency broad functional group tolerance N-methylation reaction amines using CH3OH as both C1 source solvent. Experimental results indicated that electronic effect substituents on considerably affects reactivity which Ru3 an electron-donating OMe showed highest activity. Deuterium labeling control experiments suggested dehydrogenation methanol to generate hydride species was rate-determining step reaction. Furthermore, this protocol also provided a ready approach versatile trideuterated N-methylamines under mild conditions CD3OD deuterated methylating agent.

Язык: Английский