Microwave assisted N-alkylation of amine functionalized crystal-like mesoporous phenylene-silica

Abstract

N-alkylation reaction of amine functionalized phenylene moieties in crystal-like mesoporous silica is successfully achieved with about 87% of conversion in two reaction cycles. A potassium iodide catalyzed method commonly used for the selective N-monoalkylation of aniline is adapted and optimized to the N-monoalkylation reactions of the amine functionalized periodic mesoporous phenylene-silica (NH2-PMO) under microwave irradiation with preservation of the ordered mesostructure and of the crystal-like molecular scale periodicity of the material. This functionalization opens an avenue for the preparation of new materials with different amino-alkyl groups specially designed for a desired application, namely on the adsorption or catalytic fields.

Interaction of CO2 and CH4 with Functionalized Periodic Mesoporous Phenylene–Silica: Periodic DFT Calculations and Gas Adsorption Measurements

“…-NO2, -NH-i-Pr, -CH2NH2 and -SO3H) interact with CO2 and CH4, with the purpose of optimizing resources and avoiding the synthesis of ineffective materials. These functional groups were chosen on the basis of their different polarities and of the ease of preparation of PMO-functionalized materials 17,18,21. To enable direct comparison with the results presented in the previous section, only one third of the aromatic phenylene moieties were functionalized with such groups.…”

Chiral Copper(II) Bis(oxazoline) Complexes Directly Coordinated to Amine‐Functionalized Phenylene/Biphenylene Periodic Mesoporous Organosilicas as Heterogeneous ­Catalysts

“…The intense resonance at δ= 133.5 ppm also corresponds to the sp 2 carbon atoms of the phenylene moieties from the 1,4-bis(triethoxylsilyl)benzene precursor that are not aminated during the amination process. [14,17] Other small resonances in the spectrum between δ= 10 and 75 ppm may correspond to residual carbon atoms of the alkyl chain of the surfactant. The 13 C CP MAS NMR spectrum of NH 2 BphPMO presents five resonances at δ= 126.1, 130.4, 135.2, 140.0, and 147.7 ppm that are assigned to biphenylene moieties functionalized with amine groups.…”

“…[15] Once more, this signal disappears upon coordination of CuPhBox(OTf ) 2 ] organosiliceous species, respectively, as described in the literature. [14,17] Coordination of CuMe 2 PhBox(OTf ) 2 to the NH 2 PhPMO material leads to differences in the 29 Si MAS and CP MAS NMR spectra. The T 1 signal almost disappears and the intensity of the T 2 resonance suffers a decrease with respect to the intensity of the T 3 sites.…”

“…Note that the resonance at δ= 150.3 ppm corresponds to the carbon atom of the phenylene group linked to the amine functionality. [14,17] Coordination of the copper ligands to the amine group of NH 2 PhPMO leads to enormous differences in the 13 C NMR spectra. As Cu II has a paramagnetic nucleus, the carbon nuclei close to it are not visible in the 13 C CP MAS NMR spectra.…”

Synthesis and characterization of novel periodic mesoporous organosilicas (PMOs) : versatile platforms for catalysis

“…43 VO(acac) 2 is an important homogeneous catalyst widely used for various organic transformations. 44,45 The immobilization of the VO(acac) 2 onto silica gels, mesoporous silicas, and alumina has been achieved through a wet impregnation process followed by calcination. [46][47][48] It has also been anchored onto activated carbon materials, silica materials, and clay materials by the reaction between the carbonyl group of the acac ligand and the amino group pre-grafted onto the material surfaces.…”