13061-75-1Relevant articles and documents
Development of magnesium oxide-silver hybrid nanocatalysts for synergistic carbon dioxide activation to afford esters and heterocycles at ambient pressure
Gulati, Upasana,Chinna Rajesh,Rawat, Diwan S.,Zaleski, Jeffrey M.
supporting information, p. 3170 - 3177 (2020/06/18)
Multi-metallic hybrid nanocatalysts consisting of a porous metal oxide host and metal satellite guests serve as a scaffold for multi-step transformations of divergent and energy-challenging substrates. Here we have developed a 3D porous MgO framework (Lewis basic host) with Ag0 nanoparticles (noble metal guest) for ambient pressure activation and insertion of CO2 into unsaturated alkyne substrates. The hybrid MgO@Ag-x (x = 2, 5, 7, 8 at% Ag) catalysts are synthesized by impregnating Ag+ ions in porous MgO cubes followed by reduction using NaBH4. Morphological (SEM, TEM, EDX mapping) and structural (PXRD, XPS) characterization reveal that the micron-sized hybrid cubes derive from self-assembly of ~100 nm (edge length) MgO cubes decorated with ~5 to 25 nm Ag0 NPs. Detailed XPS analysis illustrates Ag0 is present in two forms, 2 into aryl alkynes followed by SN2 coupling with allylic chlorides to afford a wide range of ester and lactone heterocycles in excellent yields (61-93%) and with low E-factor (2.8). The proposed mechanism suggests a CO2 capture and substrate assembly role for 3D porous MgO while Ag0 performs the key activation of alkyne and CO2 insertion steps. The catalyst is recyclable (5×) with no significant loss of product yield. Overall, these results demonstrate viable approaches to hybrid catalyst development for challenging conversions such as CO2 utilization in a green and sustainable manner.
Ynamide-Mediated Intermolecular Esterification
Wang, Xuewei,Yang, Yang,Zhao, Yongli,Wang, Sheng,Hu, Wenchang,Li, Jinmei,Wang, Zihao,Yang, Fengling,Zhao, Junfeng
, p. 6188 - 6194 (2020/05/26)
An ynamide-mediated one-pot, two-step intermolecular esterification via the condensation of carboxylic acids with nucleophilic hydroxyl species was reported. A broad substrate scope with respect to carboxylic acids, alcohols, and phenols was observed. The α-acyloxyenamide intermediates formed by the addition of carboxylic acids to ynamides proved to be effective acylating reagents for the esterification of alcohol and phenol derivatives with the assistance of base catalysis. Notably, the racemization of the α-chiral center of carboxylic acids can be avoided.
Ligand-free Ag(I)-catalyzed carboxylative coupling of terminal alkynes, chloride compounds, and CO2
Zhang, Xiao,Zhang, Wen-Zhen,Shi, Ling-Long,Zhu, Chuang,Jiang, Jiao-Lai,Lu, Xiao-Bing
, p. 9085 - 9089 (2013/01/13)
Simple silver(I) slats were found to be highly efficient and selective catalyst for carboxylative coupling of aryl- or alkyl-substituted terminal alkynes, CO2, and various allylic, propargylic or benzylic chlorides to exclusively yield function