- Silver/manganese dioxide nanorod catalyzed hydrogen-borrowing reactions and tert-butyl ester synthesis
-
Silver/manganese dioxide (Ag@MnO2) nanorods are synthesized and characterized by scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray powder diffraction, and X-ray photoelectron spectroscopy. It was discovered that Ag@MnO2 nanorods can realize hydrogen-borrowing reactions in high yields and are also effective for the synthesis of tert-butyl esters from aryl cyanides and tert-butyl hydroperoxide in a short period of time. Mechanistic experiments revealed that this catalytic system acts as a Lewis acid in hydrogen-borrowing reactions, while the synthesis of tert-butyl esters occurs through a radical pathway. This is the first report on the excellent catalytic activity of Ag@MnO2 nanorods as a catalyst.
- Luo, Huanhuan,Wang, Dawei,Xu, Zhaojun,Yang, Bobin,Yang, Yike
-
p. 708 - 715
(2021/03/03)
-
- A Zirconium Indazole Carboxylate Coordination Polymer as an Efficient Catalyst for Dehydrogenation-Cyclization and Oxidative Coupling Reactions
-
Rational ligand design is crucial for achieving widespread applications of coordination polymers. The preparation, structural characterisation, and catalytic applications of zirconium (IV) coordination polymer (Zr-IDA), which was derived from 1-(carboxymethyl)-1H-indazole-5-carboxylic acid are reported. The Zr-IDA catalyst contains porous and highly crystalline particles with a quasi-spherical morphology around 100 nm in size, and Zr was coordinated with both O and N as shown by FT-IR and XPS measurements. Importantly, the Zr-IDA catalyst shows great activity, selectivity and stability in the oxidative coupling of benzyl cyanides with tert-butyl hydroperoxide to afford tert-butyl peresters, and the dehydrogenation cyclization of o-phenylenediamines with aromatic alcohols to afford 1,2-disubstituted benzimidazole derivatives. Mechanistic investigations were carried out to study these reactions and the developed catalytic system in more detail.
- Sang, Xinxin,Hu, Xinyu,Tao, Rong,Zhang, Yilin,Zhu, Haiyan,Wang, Dawei
-
p. 123 - 129
(2020/02/21)
-
- Metal-free radical aromatic carbonylations mediated by weak bases
-
We report a new method of metal-free alkoxycarbonylation. This reaction involves the generation of aryl radicals from arenediazonium salts by a very weak base (HCO2Na) under mild conditions. Subsequent radical trapping with carbon monoxide and alcohols gives alkyl benzoates. The conditions (metal-free, 1 equiv. base, MeCN, r.t., 3 h) tolerate various functional groups (I, Br, Cl, CF3, SF5, NO2, ester). Mechanistic studies indicate the operation of a radical aromatic substitution mechanism.
- Koziakov, Denis,Jacobi Von Wangelin, Axel
-
supporting information
p. 6715 - 6719
(2017/08/22)
-