Heterogeneous Pd-Catalyzed Efficient Synthesis of Imidazolones via Dehydrogenative Condensation between Ureas and 1,2-Diols

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(12), P. 6906 - 6922

Published: May 26, 2022

A heterogeneously catalyzed protocol for the acceptorless dehydrogenative condensation between N,N′-disubstituted ureas and 1,2-diols to afford imidazolones was developed. Palladium nanoaggregates stabilized onto an alumina matrix with suitable acidic properties, namely, [Pd/Al2O3], designed successfully applied as efficient reusable heterogeneous nanocatalyst this relevant transformation. The methodology developed showed its wide applicability through synthesis of more than 25 moderate good yields, reaching a turnover number (TON) up 19444 initial frequency (TOF0) > 290 h–1. active nanostructured catalyst fully characterized [X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), scanning (HR-STEM), energy-dispersive X-ray (EDX), Raman spectroscopy, temperature-programmed reduction (TPR), desorption (TPD)-NH3, TPD-CO2, photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) area], mechanistic studies were performed. Moreover, other related Pd-based nanomaterials composed different or basic inorganic supports synthesized extensively compared in reaction. These revealed that presence Pd nanoparticles range sizes (average particle size 2.8 nm) over metal oxide support high density acid sites is key point activity material, γ-Al2O3 being optimum support. Furthermore, Pd–Zn cooperation effect described unactivated 1,2-diols, including ethylene glycol, ureas. Two bimetallic materials ([Pd/ZnO] [Pd(5%)–Zn(5%)/Al2O3]) also properly. materials, well [Pd/Al2O3] system combination catalytic amounts ZnO, selectivity 1,2-diols. nature all systems demonstrated, reusability catalysts proven.

Language: Английский

The chemistry of 1,4-dihydropyrrolo[3,2-b]pyrroles

Advances in heterocyclic chemistry, Journal Year: 2022, Volume and Issue: unknown, P. 335 - 409

Published: Jan. 1, 2022

Language: Английский

Novel pyrrolo[2,3-b]pyridine and pyrrolo[2,3-d] pyrimidine derivatives: Design, synthesis, and structure elucidation

Bulletin of the Chemical Society of Ethiopia, Journal Year: 2023, Volume and Issue: 37(4), P. 983 - 992

Published: May 12, 2023

ABSTRACT. A cyclo condensation reaction is an effective method for a two-component of 2-amino-1,5-diphenyl-1H-pyrrole-3-carbonitrile 3a-c and active methylene compounds in acetic acid catalytic hydrochloric to produce new substituted 1H-pyrrolo[2,3-b]pyridine 4a-c, 5a-c, 6a-c have been established. Additionally, series 1H-pyrrolo[2,3-d]pyrimidines 7a-c 8a-c could be synthesized utilizing feasible efficient approach, including urea thiourea substrates. Spectroscopic data IR, MS, 1H, 13C NMR, as well elemental analyses, elucidated these compounds' structures. KEY WORDS: 1H-Pyrrolo[2,3-b]pyridine, 1H-Pyrrolo[2,3-d]pyrimidines, Active compounds Bull. Chem. Soc. Ethiop. 2023, 37(4), 983-992. DOI: https://dx.doi.org/10.4314/bcse.v37i4.14

Language: Английский