117538-86-0Relevant academic research and scientific papers
Enhancement of solid base activity for porous boron nitride catalysts by controlling active structure using post treatment
Hayashi, Shigenobu,Ishihara, Tatsumi,Jimura, Keiko,Kim, Yoonyoung,Nakamura, Shohei,Song, Jun Tae,Takagaki, Atsushi,Watanabe, Motonori,Yamada, Kanta,Yoshida, Masaaki
, (2020)
Porous boron nitride (BN) was synthesized using a pyrolysis method in conjunction with varying NH3 flow rates, followed by washing as a post-treatment. The performance of this material as a solid base catalyst was assessed. It was found that th
Utilization of hexagonal boron nitride as a solid acid–base bifunctional catalyst
Torii, Shusaku,Jimura, Keiko,Hayashi, Shigenobu,Kikuchi, Ryuji,Takagaki, Atsushi
, p. 176 - 184 (2017)
This work explores the use of hexagonal boron nitride (h-BN), a graphite-like compound, as a novel catalyst with base and acid functionalities. For use as a solid catalyst, the layered structure of h-BN was disrupted by ball-milling, exposing boron and ni
Porous Boron Nitride as a Weak Solid Base Catalyst
Nakamura, Shohei,Takagaki, Atsushi,Watanabe, Motonori,Yamada, Kanta,Yoshida, Masaaki,Ishihara, Tatsumi
, p. 6033 - 6039 (2020/10/19)
Porous boron nitride was synthesized by pyrolysis from boric acid and urea mixed in varying molar ratios. The boron nitride prepared had high surface areas ranging from 376 to 647 m2 g?1 with both microporous and mesoporous structures. The sample prepared with a urea-to-boric acid molar ratio of 5 exhibited the highest pore volume with the highest surface area of mesopores. Boron-K edge X-ray absorption fine structure spectroscopy revealed that the surface structure consisted of BN3 sites along with BN2O, BNO2, and BO3 sites. Fourier transform infrared (FTIR) spectroscopy indicated the formation of amino and hydroxyl groups on the surface. Analysis using color indicator reagents and deuterated chloroform-adsorbed FTIR results indicated that the porous boron nitride had very weak base sites of strength +7.2>H?≥+6.3. Porous boron nitride exhibited a high activity for the nitroaldol reaction with a high selectivity for nitroalkene (>97 %). A good correlation was observed between the catalytic activity of the boron nitride catalysts and their porous structures.
Deep eutectic solvent as solvent and catalyst: One-pot synthesis of 1,3-dinitropropanes: Via tandem Henry reaction/Michael addition
Colombo Dugoni, Greta,Mele, Andrea,Sacchetti, Alessandro
, p. 8395 - 8401 (2020/11/05)
The Henry reaction was performed using microwave heating within the deep eutectic solvent (DES) choline chloride/urea (ChCl/urea) which acted as both the catalyst and solvent for the reaction. The optimisation of the conditions (temperature, heating mode,
Co-Polymeric Nanosponges from Cellulose Biomass as Heterogeneous Catalysts for amine-catalyzed Organic Reactions
Riva, Laura,Punta, Carlo,Sacchetti, Alessandro
, p. 6214 - 6222 (2020/10/02)
Heterogeneous catalysts prepared from biomass waste sources are attracting increasing interest. The reasons rely on the possibility of combining the virtuous approach of circular economy with the consolidated advantages of heterogeneous catalysis, namely the recycling of the system and the possibility to drive selectivity towards desired products. Herein we report a highly porous cellulose-based nanosponge (CNS) and its use as a recoverable catalyst for Henry and Knoevenagel reactions, two classical amino-catalyzed transformations. The material is obtained by cross-linking between TEMPO-oxidized cellulose nanofibers (TOCNF) and branched polyethyleneimine 25 kDa (bPEI) in the presence of citric acid. CNS have been developed as sorbent materials for water remediation but their use as heterogeneous catalysts was never investigated. The fully characterized micro- and nano-porous system guarantees a complete penetration of CNS, allowing reagents to diffuse within. Indeed, by modulating reaction conditions (catalyst loading, temperature, solvent, microwave versus conventional heating, relative ratio of reagents) it was possible to drive selectivity towards the desired products, while maintaining high efficiency in terms of conversion. The catalyst could be re-used several times without losing in catalytic efficiency. In most cases the products’ distribution is quite different from homogeneous conditions, this much more emphasizing the importance of this heterogeneous solution.
Base-catalyzed reactions enhanced by solid acids: Amine-catalyzed nitroaldol (Henry) reactions enhanced by silica gel or mesoporous silica SBA-15
Tanemura, Kiyoshi,Suzuki, Tsuneo
supporting information, p. 392 - 396 (2017/12/28)
The reactions of various aldehydes with CH3NO2 catalyzed by Et3N, n-C6H13NH2, and Me2N(CH2)2NH2 were accelerated by the addition of silica gel to give aromatic (aliphatic) β-nitroalcohols, aromatic nitroalkenes, and aromatic 1,3-dinitroalkanes, respectively. Mesoporous silica SBA-15 showed higher activity than silica gel for the synthesis of aromatic nitroalkenes by the reactions of the corresponding aldehydes with CH3NO2 catalyzed by n-C6H13NH2.
Ethylenediamine-functionalized magnetic Fe3O4@SiO2 nanoparticles: cooperative trifunctional catalysis for selective synthesis of nitroalkenes
Xue, Fengjun,Dong, Yahao,Hu, Peibo,Deng, Yanan,Wei, Yuping
, p. 73684 - 73691 (2015/09/15)
A magnetically separable trifunctional nanocatalyst Fe3O4@SiO2-NH2 was synthesized and characterized by TEM, FT-IR, XRD, TGA, and EA. The designed nanocatalyst was found to be highly active for selective synthesis of nitroalkenes with nitromethane and aromatic aldehyde through cooperative trifunctional catalysis of primary amine, secondary amine and Si-OH groups on the surface of the catalyst. Under the optimized conditions, various representative substrates were extended to obtain the corresponding products in moderate or excellent yields. After the reaction, the trifunctional nanocatalyst was easily recovered and recycled by applying an external magnet. In addition, a possible cooperative trifunctional catalysis mechanism was also proposed.
Compartmentalization of incompatible reagents within Pickering emulsion droplets for one-pot cascade reactions
Yang, Hengquan,Fu, Luman,Wei, Lijuan,Liang, Jifen,Binks, Bernard P.
supporting information, p. 1362 - 1371 (2015/02/19)
It is a dream that future synthetic chemistry can mimic living systems to process multistep cascade reactions in a one-pot fashion. One of the key challenges is the mutual destruction of incompatible or opposing reagents, for example, acid and base, oxidants and reductants. A conceptually novel strategy is developed here to address this challenge. This strategy is based on a layered Pickering emulsion system, which is obtained through lamination of Pickering emulsions. In this working Pickering emulsion, the dispersed phase can separately compartmentalize the incompatible reagents to avoid their mutual destruction, while the continuous phase allows other reagent molecules to diffuse freely to access the compartmentalized reagents for chemical reactions. The compartmentalization effects and molecular transport ability of the Pickering emulsion were investigated. The deacetalization-reduction, deacetalization-Knoevenagel, deacetalization-Henry and diazotization-iodization cascade reactions demonstrate well the versatility and flexibility of our strategy in processing the one-pot cascade reactions involving mutually destructive reagents. (Figure Presented).
One-pot synthesis of 1 ,3-dinitroalkanes catalysed by nickel species
Gao, Min,Wei, Yu-Ping
, p. 146 - 148 (2013/07/05)
The reaction of aromatic aldehydes with nitromethane afforded a one-pot preparation of 1,3-dinitroalkanes in the presence of a nickel catalytic system. This efficient and simple method proceeded with moderate to high yields (56-99%) under mild conditions.
Silica grafted polyethylenimine as heterogeneous catalyst for condensation reactions
Ribeiro, Sonia M.,Serra, Arménio. C.,Gonsalves, A.M. D'A. Rocha
experimental part, p. 126 - 133 (2012/02/01)
Primary amine groups were attached to a silica surface by using α,ω-diamines derivatives and (3-glycidyloxypropyl)-trimethoxysilane activation. The same activation was used to graft polyethylenimine, which also contains secondary and tertiary amine groups. These silica aminated structures were tested as heterogeneous catalysts in nitroaldol condensation with nitromethane, the derivative with the polyethylenimine moiety being the more active catalyst. This catalyst also showed efficiency in the Knoevenagel condensation of benzaldehydes with ethyl cyanoacetate under very mild reaction conditions and showed much the same efficiency when used in consecutive reaction runs. A reaction mechanism with participation of the several amine groups of the catalysts is discussed.
