The C–N cross coupling reaction of aryl chlorides with various alkyl/aryl amines catalyzed by copper nanoparticles impregnated on alumina/silica support (Cu(0)@Al2O3/SiO2) was investigated. The prepared catalyst was characterized for its intrinsic physico-chemical and textural properties using XRD, XPS, HR-TEM, BET surface area, SEM-EDAX, H2-TPR and ICP-AES techniques. The catalyst exhibits excellent reactivity and efficacy in the cross-coupling of a wide range of alkyl/aryl amines including challenging anilines with aryl chlorides. The catalyst offers significant advantages such as brevity, milder reaction conditions, excellent yields and high functional group tolerance for C–N cross coupling when compared with the other reported methods. Moreover, this atom-economical methodology does not require an additional ligand or co-catalyst/activator. The Cu(0)@Al2O3/SiO2 catalyst was efficiently applied to a gram scale synthesis of 7-chloro-4-(4-(2-nitrophenyl)piperazin-1-yl)quinolone (2k). The robustness of the catalyst was examined by reusing it for five consecutive runs.
The Royal Society of Chemistry