1644-00-4Relevant articles and documents
Light-Promoted C–N Coupling of Aryl Halides with Nitroarenes
Li, Gang,Yang, Liu,Liu, Jian-Jun,Zhang, Wei,Cao, Rui,Wang, Chao,Zhang, Zunting,Xiao, Jianliang,Xue, Dong
supporting information, p. 5230 - 5234 (2021/02/05)
A photochemical C–N coupling of aryl halides with nitroarenes is demonstrated for the first time. Catalyzed by a NiII complex in the absence of any external photosensitizer, readily available nitroarenes undergo coupling with a variety of aryl halides, providing a step-economic extension to the widely used Buchwald–Hartwig C–N coupling reaction. The method tolerates coupling partners with steric-congestion and functional groups sensitive to bases and nucleophiles. Mechanistic studies suggest that the reaction proceeds via the addition of an aryl radical, generated from a NiI/NiIII cycle, to a nitrosoarene intermediate.
Modified graphene supported Ag-Cu NPs with enhanced bimetallic synergistic effect in oxidation and Chan-Lam coupling reactions
Choudhary, Anu,Gupta, Monika,Kaur, Manpreet,Paul, Satya,Sharma, Chandan,Sharma, Nitika
, p. 30048 - 30061 (2020/10/06)
Herein, well dispersed Ag-Cu NPs supported on modified graphene have been synthesized via a facile and rapid approach using sodium borohydride as a reducing agent under ambient conditions. Dicyandiamide is selected as an effective nitrogen source with TiO2 as an inorganic material to form two kinds of supports, labelled as TiO2-NGO and NTiO2-GO. Initially, the surface area analysis of these two support materials was carried out which indicated that N-doping of GO followed by anchoring with TiO2 has produced support material of larger surface area. Using both types of supports, ten nano-metal catalysts based on Ag and Cu were synthesized. Benefiting from the bimetallic synergistic effect and larger specific surface area of TiO2-NGO, Cu?Ag-TiO2-NGO is found to be a highly active and reusable catalyst out of other synthesized catalysts. It exhibits excellent catalytic activity for oxidation of alcohols and hydrocarbons as well as Chan-Lam coupling reactions. The nanocatalyst is intensively characterized by BET, SEM, HR-TEM, ICP-AES, EDX, CHN, FT-IR, TGA, XRD and XPS. This journal is
Diamines as interparticle linkers for silica-titania supported PdCu bimetallic nanoparticles in Chan-Lam and Suzuki cross-coupling reactions
Jamwal, Babita,Kaur, Manpreet,Sharma, Harsha,Khajuria, Chhavi,Paul, Satya,Clark
, p. 4919 - 4928 (2019/03/26)
A series of highly efficient amine functionalized SiO2-TiO2 supported bimetallic PdCu catalysts with varied metal composition have been synthesized. Ethane-1,2-diamine, butane-1,4-diamine and hexane-1,6-diamine were employed as interparticle linkers for amine functionalization of a SiO2-TiO2 support material so as to study the effect of pendant chain length on stabilization and immobilization of bimetallic nanoparticles. The shortest carbon chain length on the support provided the best results, which may be due to the trapping of metal nanoparticles more efficiently by the basic nitrogen sites. The catalytic activities of these materials were evaluated for C-N and C-C coupling reactions. The most active catalyst, Pd1Cu1@12DA-STS, was characterized by various techniques including SEM, HR-TEM, ICP-AES, XRD, FTIR, EDX, CHN analysis and TGA studies. Moreover, the synthesized catalyst was found to be recyclable for up to five runs without significant loss of activity.
