NiO@TPP-HPA As an Efficient Integrated Nanocatalyst and Anti-Liver Cancer Agent. Synthesis of 2-Substituted Indoles

A new tetraphenylporphyrin-heteropolyacid (TPP-HPA) nanohybrid material is synthesized and loaded onto NiO nanoparticles to achieve an efficient heterogeneous catalyst. Then, the new inorganic-organic nanohybrid catalyst NiO@TPP-HPA was introduced as an efficient and recoverable catalyst in the synthesis of 2-substituted indoles through condensation of indole with malononitrile and different aldehydes at solventless condition. The nanohybrid material was characterized by FESEM, EDS, XRD, FTIR and TGA. The attained findings showed that NiO@TPP-HPA is an effective catalyst toward the desired condensation reaction and provided good recyclability for at least six runs without significant loss of activity. Moreover, it has been shown that preparation of 2-substituted indoles occurs by the way of radical mechanism, indicating •O2−, h+ and OH• as contributing species. In addition, the hot-filtration experiment proved that NiO@TPP-HPA is a steady nanocatalyst in the current multicomponent synthesis. Moreover, the in-vitro toxicity of NiO@TPP-HPA was inspected toward HepG2 cell line through an MTT assay, confirming that this nanomaterial is a potential agent against the desired cell line. Therefore, this nanocomposite can be treated as an anti-liver cancer agent.