1173294-80-8Relevant articles and documents
Monodisperse CuPd alloy nanoparticles as efficient and reusable catalyst for the C (sp2)–H bond activation
Huang, Fei,Wang, Feifan,Hu, Qiyan,Tang, Lin,Xu, Dongping,Fang, Yang,Zhang, Wu
, (2021/03/17)
Metal-catalyzed selective activation of C–H bonds is very important for the construction of a variety of biologically active molecules. Supported alloy nanoparticles are of great interest in various catalytic applications due to the synergistic effects between different metals. Here, well-dispersed CuPd alloy nanoparticles supported on reduced graphene oxide (rGO) were synthesized and found to be highly efficient and recyclable catalyst for the chelation-assisted C (sp2)–H bond activation. Aromatic ketones or esters were synthesized via the cross-dehydrogenative coupling (CDC) reaction between 2-arylpyridines and alcohols or acids. Moreover, the catalyst was recovered and used for five times without significantly losing activity.
Palladium-catalyzed decarboxylative, decarbonylative and dehydrogenative C(sp2)-H acylation at room temperature
Hossian, Asik,Manna, Manash Kumar,Manna, Kartic,Jana, Ranjan
, p. 6592 - 6603 (2017/08/16)
Over the past few decades, an impressive array of C-H activation methodology has been developed for organic synthesis. However, due to the inherent inertness of the C-H bonds (e.g. ～110 kcal mol-1 for the cleavage of C(aryl)-H bonds) harsh reaction conditions have been realized to overcome high energetic transition states resulting in a limited substrate scope and functional group tolerance. Therefore, the development of mild C-H functionalization protocols is in high demand to exploit the full potential of the C-H activation strategy in the synthesis of a complex molecular framework. Although, electron-rich substrates undergo electrophilic metalation under relatively mild conditions, electron-deficient substrates proceed through a rate-limiting C-H insertion under forcing conditions at high temperature. In addition, a stoichiometric amount of toxic silver salt is frequently used in palladium catalysis to facilitate the C-H activation process which is not acceptable from the environmental and industrial standpoint. We report herein, a Pd(ii)-catalyzed decarboxylative C-H acylation of 2-arylpyridines with α-ketocarboxylic acids under mild conditions. The present protocol does not require stoichiometric silver(i) salts as additives and proceeds smoothly at ambient temperature. A novel decarbonylative C-H acylation reaction has also been accomplished using aryl glyoxals as acyl surrogates. Finally, a practical C-H acylation via a dehydrogenative pathway has been demonstrated using commercially available benzaldehydes and aqueous hydroperoxides. We also disclose that acetonitrile solvent is optimal for the acylation reaction at room temperature and has a prominent role in the reaction outcome. Control experiments suggest that the acylation reaction via decarboxylative, decarbonylative and dehydrogenative proceeds through a radical pathway. Thus we disclose a practical protocol for the sp2 C-H acylation reaction.
Palladium(II)-Catalyzed C-H Acylation with Arylglycine Derivatives
Fan, Weizheng,Su, Jiapeng,Feng, Bainian
, p. 2033 - 2036 (2015/09/01)
A novel palladium(II)-catalyzed ortho acylation of arenes with arylglycines in the presence of Cu(OAc)2 and K2S2O8 to afford the benzophenones was developed. This direct C-H acylation is suitable for a broad range of substrates. The control experiments suggested a possible oxidative addition mechanism.
