45821-44-1Relevant articles and documents
Synergistic Nanostructured MnOx/TiO2 Catalyst for Highly Selective Synthesis of Aromatic Imines
Sudarsanam, Putla,K?ckritz, Angela,Atia, Hanan,Amin, Mohamad Hassan,Brückner, Angelika
, p. 1990 - 1997 (2021/02/27)
This work reports the development of a synergistic nanostructured MnOx/TiO2 catalyst, with highly dispersed MnOx nanoparticles (4.5±1 nm) on shape-controlled TiO2 nanotubes (8–11 nm width and 120–280 nm length), for selective synthesis of valuable aromatic imines at industrially important conditions. Pristine TiO2 nanotubes exhibited 97 % imine selectivity at a 38.3 % benzylamine conversion, whereas very low imine selectivity was obtained over commercial TiO2 materials, indicating the catalytic significance of shape-controlled TiO2 nanotubes. The MnOx nanoparticle/TiO2 nanotube (10 wt% Mn) catalyst calcined at 400 °C showed the best activity with 95.6 % benzylamine conversion and 99.9 % imine selectivity. This catalyst exhibited good recyclability for four times and is effective for converting numerous benzylamines into higher yields of imines. The high catalytic performance of MnOx/TiO2 nanotubes was attributed to higher number of redox sites (Mn3+), high dispersion of Mn species, and shape-controlled structure of TiO2, indicating that this catalyst could be a promising candidate for selective oxidation reactions.
Methyl-triflate-mediated dearylmethylation of: N -(arylmethyl)carboxamides via the retro-Mannich reaction induced by electrophilic dearomatization/rearomatization in an aqueous medium at room temperature
Peng, Hui,Ma, Jinhui,Luo, Wenkun,Zhang, Guangwen,Yin, Biaolin
supporting information, p. 2252 - 2256 (2019/05/17)
We have developed a protocol for the dearylmethylation of N-(arylmethyl)carboxamides under metal-free conditions in an aqueous medium at room temperature. This protocol involves methyl triflate-mediated successive C-C and C-N bond cleavages (retro-Mannich reaction) induced by electrophilic dearomatization/rearomatization. The dearomatization/rearomatization strategy can be expected to inspire the development of novel transformations based on the C-C bond cleavage in an environmentally benign manner.
Structural characteristics and catalytic performance of nanostructured Mn-doped CeO2 solid solutions towards oxidation of benzylamine by molecular O2
Rangaswamy, Agolu,Venkataswamy, Perala,Devaiah, Damma,Ramana, Singuru,Reddy, Benjaram M.
, p. 136 - 147 (2017/01/03)
This work reports a thorough investigation of nanosized Mn-doped ceria (Ce0.7Mn0.3O2-δ, CM) as an efficient catalyst for oxidation of benzylamine under solvent-free conditions. These catalysts were prepared by a coprecipitation method followed by calcination at 773 and 1073?K. Effect of Mn doping was examined by a variety of characterization techniques. XRD results confirmed formation of single-phase Ce-O-Mn solid solution, and TEM studies showed nanosized nature of particles. BET surface area of CeO2 was significantly enhanced after Mn incorporation. Raman, XPS and H2-TPR results revealed that Mn cations in ceria lattice increase concentration of structural oxygen vacancies and reducibility of ceria. Among various catalysts, the CM calcined at 773?K exhibited a high conversion (~71%), product selectivity (~99.8%), and excellent stability. The better performance has been proved to be due to synergetic interaction between Ce and Mn ions thereby enhanced surface area, improved reducibility, and increased surface adsorbed oxygen species.