18263-30-4Relevant academic research and scientific papers
Hollow Carbon Sphere Nanoreactors Loaded with PdCu Nanoparticles: Void-Confinement Effects in Liquid-Phase Hydrogenations
Dong, Chao,Liu, Jian,Su, Panpan,Wang, Guang-Hui,Ye, Run-Ping,Yu, Qun
, p. 18374 - 18379 (2020)
Nanoreactors with hollow structures have attracted great interest in catalysis research due to their void-confinement effects. However, the challenge in unambiguously unraveling these confinement effects is to decouple them from other factors affecting catalysis. Here, we synthesize a pair of hollow carbon sphere (HCS) nanoreactors with presynthesized PdCu nanoparticles encapsulated inside of HCS (PdCu?HCS) and supported outside of HCS (PdCu/HCS), respectively, while keeping other structural features the same. Based on the two comparative nanoreactors, void-confinement effects in liquid-phase hydrogenation are investigated in a two-chamber reactor. It is found that hydrogenations over PdCu?HCS are shape-selective catalysis, can be accelerated (accumulation of reactants), decelerated (mass transfer limitation), and even inhibited (molecular-sieving effect); conversion of the intermediate in the void space can be further promoted. Using this principle, a specific imine is selectively produced. This work provides a proof of concept for fundamental catalytic action of the hollow nanoreactors.
Stereocontrolled synthesis of anticancer β-lactams via the Staudinger reaction
Banik, Bimal K.,Banik, Indrani,Becker, Frederick F.
, p. 3611 - 3622 (2007/10/03)
Stereocontrolled synthesis of novel β-lactams using polyaromatic imines following the Staudinger reaction has been accomplished. The effects of domestic microwave irradiation on this type of reaction have been investigated. Formation of trans-β-lactams has been explained through isomerization of the enolates formed during the reaction of acid chloride (equivalent) with imines in the presence of triethylamine. A donor-acceptor complex pathway is believed to be involved in the formation of cis-β-lactams. The effect of a peri hydrogen has been found to be significant in controlling the stereochemistry of the resulting β-lactams. SAR has identified β-lactams with anticancer activity. The presence of an acetoxy group has proven obligatory for their anticancer activity.
