6946-35-6Relevant articles and documents
Catalytic Activity of Quaternary Ammonium Poly(methylstyrene-co-styrene) Resin in an Organic Solvent/Alkaline Solution
Wu, Ho-Shing,Lee, Chun-Shen
, p. 217 - 223 (2001)
The reaction of 4-methoxyphenylacetic acid with n-bromobutane using triphase catalysis in a dichloromethane/alkaline solution was investigated. Meanwhile, the lab-produced resins and the commercial ion-exchange resin (triphase catalyst) were characterized in terms of the density of active sites, thermal stability, imbibed solvent composition, and reuse of the resin. The amount of active sites in the resin was characterized by EA, TGA, and Volhard methods. The imbibed amounts of organic solvent and water and the volume ratios for lab-produced resins were larger than those for commercial resins. The degradation of the catalyst due to temperature is greater than that due to base concentration.
Encapsulation of heteropolyacids within hollow microporous polymer nanospheres for sustainable esterification reaction
He, Zhiwei,Huang, Kun,Song, Chunmei,Wang, Huaqing,Yu, Haitao,Zhang, Li
, (2021/10/25)
Herein, the Keggin structural phosphotungstic acid (HPW) has been successfully encapsulated within hollow microporous polymer nanospheres (H-MPNs) by a “ship-in-bottle” approach. The H-MPNs are formed by self-assembly induced by hyper-crosslinking of polylactide-b-polystyrene (PLA-b-PS). The obtained catalysts (HPW@H-MPNs) exhibit more sustainable availability than the previously reported HPW-supported catalysts in esterification reaction. This excellent sustainability can be attributed to the stable microporous channels in H-MPNs which are smaller than the molecular size of HPW, thereby effectively preventing the HPW from leaking out. Moreover, such catalysts also perform well in terms of catalytic activity and universality because of the combination of a hollow structure in the interior and permeable pore channels in the shells. This type of polymer carrier and general encapsulation method may provide a new strategy for developing more sustainable catalysts for various chemical reactions.
Carboxyboronate as a Versatile In Situ CO Surrogate in Palladium-Catalyzed Carbonylative Transformations
Tien, Chieh-Hung,Trofimova, Alina,Holownia, Aleksandra,Kwak, Branden S.,Larson, Reed T.,Yudin, Andrei K.
supporting information, p. 4342 - 4349 (2020/12/25)
The application of carboxy-MIDA-boronate (MIDA=N-methyliminodiacetic acid) as an in situ CO surrogate for various palladium-catalyzed transformations is described. Carboxy-MIDA-boronate was previously shown to be a bench-stable boron-containing building block for the synthesis of borylated heterocycles. The present study demonstrates that, in addition to its utility as a precursor to heterocycle synthesis, carboxy-MIDA-boronate is an excellent in situ CO surrogate that is tolerant of reactive functionalities such as amines, alcohols, and carbon-based nucleophiles. Its wide functional-group compatibility is highlighted in the palladium-catalyzed aminocarbonylation, alkoxycarbonylation, carbonylative Sonogashira coupling, and carbonylative Suzuki–Miyaura coupling of aryl halides. A variety of amides, esters, (hetero)aromatic ynones, and bis(hetero)aryl ketones were synthesized in good-to-excellent yields in a one-pot fashion.