C–H Amidation and Amination of Arenes and Heteroarenes with Amide and Amine using Cu-MnO as a Reusable Catalyst under Mild Conditions

Abstract

An atom-economical and efficient route for the direct amidation and amination of aryl C−H bonds using our synthesized recyclable heterogeneous Cu-MnO catalyst is reported here. The direct C−H amidation was carried out using a simple amide without any preactivated coupling partner, and simple air was used as the sole oxidant. The reaction proceeds very smoothly with a broad range of substrates containing numerous functional groups in very good to excellent yields. Direct C−H aminations with a secondary amine were carried out under base-, ligand-, and external oxidant-free conditions in very good to excellent yields in very mild conditions. Both the amidation and amination can be scaled up on a gram scale with similar yields. The major advantage is that our catalyst is recyclable and reused several times without any significant loss of reactivity.

Enantioselective Catalytic C-H Amidations: An Highlight

“…Moreover, these reactions have been associated with a large range of metals (Co, Ru, Ir and Rh) and source of chirality (from classical chiral ligands or chiral carboxylic acids to chiral-at-metal complexes). Capitalizing on these seminal and remarkable achievements, challenges to be addressed now could be the development of enantioselective iron-catalyzed reactions [11], the development of reusable chiral catalysts [68], or the development of enantioselective C-H amidation in tandem processes [69]. To date, only dioxazolones have been reported as efficient substrates on these enantioselective transformations.…”

Metal Nanoparticles as Sustainable Tools for C–N Bond Formation via C–H Activation

“…Recently, the same group proposed a different protocol for the C–H amidation of 8-aminoquinoline benzamides 10 with different cyclic amides 11 using their Cu-MnO heterogeneous catalyst and air as oxidant ( Scheme 4 ) [ 64 ]. The authors hypothesized that their MnO support may help the electron transfer pathway in the reductive elimination by working as an electron-transfer mediator (ETM).…”

“…Different C–H amination processes have been developed with the use of copper based nanocatalysts, employing as nitrogen sources primary [ 71 , 72 ] or secondary [ 64 , 72 , 73 , 74 ] amines, as well as ammonia [ 75 ].…”

“…Very recently, the same group employed copper-supported on spherical MnO in the C–H amination of 8-aminoquinoline benzamides 10 ( Scheme 12 ) [ 64 ]. In comparison with the results previously described for the amidation reaction, the direct amination proceeds under milder reaction conditions.…”

Recent Advances in Base Metal (Copper, Cobalt and Nickel)-Catalyzed Directed C—H Amination

“…磺酰亚胺作 为该反应的胺化试剂, 反应生成的磺酰亚胺化产物可以 通过自由基断裂来制备游离的苯胺, 最终实现了一锅两 步法合成苯胺. 最近, Ghosh 课题组 [18] [19] 首次以有机叠氮化物作为胺化 试剂实现了 Rh(III)催化碳氢键胺化反应以来, 该领域获 得了迅猛的发展. 2014 年, 朱强课题组 [20] 首次将其应用 于铜催化碳氢键胺化反应(Scheme 8, a).…”