Ru@PsIL‐Catalyzed Synthesis of N‐Formamides and Benzimidazole by using Carbon Dioxide and Dimethylamine Borane

Abstract

This work reports the synthesis and characterization of ruthenium nanoparticles (Ru NPs) supported on polymeric ionic liquids (PILs). This catalyst shows high catalytic activity towards the N‐formylation of amines and synthesis of benzimidazoles from 1,2‐diamines and carbon dioxide (CO2) by reductive dehydrogenation of dimethylamine borane. This methodology shows excellent functional group tolerance with broad substrate scope towards the synthesis of N‐formamides and benzimidazoles. Interestingly, this protocol also provides the tandem reduction of 2‐nitroamines and CO2 to synthesize benzimidazoles. It was proposed that the ionic liquid phase of the polymer plays pivotal roles such as assisting the stabilization of nanoparticles electrostatically, providing an ionic environment, and controlling the easy access of the substrates/reagents to the active sites. The developed methodology utilizes CO2 as a C1 source and water/ethanol as a green solvent system. Additionally, the catalyst was found to be recyclable in nature and shows five consecutive recycling runs without significant loss in its activity.

A decennary update on applications of metal nanoparticles (MNPs) in the synthesis of nitrogen- and oxygen-containing heterocyclic scaffolds

“…Bhanage et al reported that ruthenium nanoparticles supported on polymeric ionic liquids (Ru@PsIL) catalyzed the synthesis of N-formamides (123f/40d) and benzazoles (123g) such as benzimidazole or benzoxazole from carbon dioxide and dimethylamine borane (DMAB) in water : ethanol (1 : 1) as a green solvent and K 2 CO 3 as the base (Scheme 177). 318 A polymeric ionic liquid (PsIL) were synthesized from Merrield peptide resin and 1,2-dimethyl-1H-imidazole, which was treated with RuCl 3 and NaBH 4 for the immobilization of RuNPs onto PsIL. The good recyclability of the developed catalyst was observed up to the h catalytic run without loss in catalytic activity, and a negligible amount of leaching was observed.…”

“…The present protocol for the synthesis of cyclic thiourea has the advantages of operational at rt and proceeds without the formation of pernicious hydrogen sulde gas in comparison with that in the literature. [370][371][372][373][374][375] MgO NPs immobilized on IL-based periodic mesoporous organosilica (Mg@PMOL-IL) catalyzed the cyclocondensation of isatins (5c), 1,3-dicarbonyl compounds such as dimedone or 1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione (7f) and N-phenylacetyl pyridinium bromides (318), providing a reasonable approach for the synthesis of spirooxindole-furan derivatives (Scheme 208) in excellent yields. 376 The key catalyst was synthesized via the deposition of MgO NPs on PMOL-IL, presynthesized from tetramethoxysilane and 1,3-bis(3trimethoxysilylpropyl) imidazolium chloride using Pluronic P123 as a structure-directing agent.…”

Facile N‐Formylation of Amines on Magnetic Fe3O4−CuO Nanocomposites

“…[29] They have been widely applied in the synthesis of pharmaceutically active compounds such as 1,2-dihydroquinolines, [30] nitrogen-containing heterocycles, [31] fluoroquinolines, [32] and imidazoles. [33] Over the past few years, a variety of N-formylation methods have been reported. [34][35] Most of the reported methods for N-formylation have limitations such as low yield, the requirement of an inert atmosphere, high reaction temperature, expensive reagents, and harsh conditions, which result in tedious processes, and even occasionally require protection of acid functional groups.…”

CO2 Methanation via Amino Alcohol Relay Molecules Employing a Ruthenium Nanoparticle/Metal Organic Framework Catalyst

“…Figure 2 b presents the Ru 3p 3/2 spectrum of the Ru/ SION-105 catalyst. The binding energy (BE) of 462.4 eV was attributed to metallic Ru, whereas the low-intensity peak at 463.7 eV [39] may be related to the formation of Ru-O linkages between the edge of the Ru NPs and the carboxyl groups of the MOF. This interaction may be relevant in controlling the size and dispersion of the Ru NPs on the surface of SION-105.…”