1173294-81-9Relevant articles and documents
A Strategy for Amide C-N Bond Activation with Ruthenium Catalyst: Selective Aromatic Acylation
Li, Wenkuan,Zhang, Sheng,Feng, Xiujuan,Yu, Xiaoqiang,Yamamoto, Yoshinori,Bao, Ming
supporting information, p. 2521 - 2526 (2021/04/05)
A strategy for amide C-N bond activation with ruthenium catalyst is described for the first time. The in situ formed bis-cycloruthenated complexes were demonstrated to be the key active species with superior oxidative addition ability to an inert amide C-N bond. The direct C-H bond activation of 2-arylpyridines followed by the amide C-N bond activation took place in the presence of a ruthenium precatalyst to produce monoacylation products in moderate to good yields. Synthetically useful functional groups, such as halogen atoms (F and Cl), ester, acetyl, and vinyl, remained intact during tandem C-H/C-N bond activation reactions.
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.
