multicomponent reactions in which three or more substrates are streamlined towards the formation of a single product enable the development of novel synthetic strategies.1 In particular, the Cu(I)-catalyzed four-component coupling of amines, aldehydes, alkynes and CO2 is a versatile and attractive method for the synthesis of oxazolidinones, a class of heterocyclic scaffold exhibiting applications in medicinal
介绍 多组分反应的效率和选择性,其中三种或多种底物被简化以形成单一产物,使得新型合成策略的开发成为可能。1特别是,Cu(I) 催化的胺、醛、炔和 CO 2的四组分偶联是合成恶唑烷酮的一种通用且有吸引力的方法,恶唑烷酮是一类杂环支架,在药物化学(针对抗生素的新型抗生素)中展示了应用。微生物耐药性、抗结核活性、通过拓扑异构酶 II 抑制的抗病毒和抗癌药物)、2分子化学(对映选择性催化中的手性助剂)3和材料科学(聚合物杀菌膜、阻燃剂)4由于其独特的结构和氢键特性。 恶唑烷酮合成的金属催化四组分偶联反应领域正在迅速发展,5但大多数催化系统都是基于 Cu(I) 6(很少涉及 Cu(II) 催化前体7)或其组合与工程化的溶剂如离子液体,以增强所得催化系统的可回收性。8 从机理的角度来看,Li及其同事报道的开创性工作提出了一种通过形成相应的炔丙胺中间体进行A 3偶联羧基环化的机制,并指出了胺和CO 2之间的协同效应。9后来,Hu
Monodisperse nickel-nanoparticles for stereo- and chemoselective hydrogenation of alkynes to alkenes
作者:Kathiravan Murugesan、Ahmad S. Alshammari、Manzar Sohail、Matthias Beller、Rajenahally V. Jagadeesh
DOI:10.1016/j.jcat.2018.12.018
日期:2019.2
Here, we report the use of monosaccharides for the preparation of novel nickel nanoparticles (NP), which constitute selective hydrogenation catalysts. For example, immobilization of fructose and Ni(OAc)2 on silica and subsequent pyrolysis under inert atmosphere produced graphitic shells encapsulated Ni-NP with uniform size and distribution. Interestingly, fructose acts as structure controlling compound