Efficient and sustainable Co3O4 nanocages based nickel catalyst: A suitable platform for the synthesis of quinoxaline derivatives

Abstract

The Co 3 O 4 nanocages has been synthesized based on the Kirkendall effect involving the thermal decomposition of prussian blue analogue Co 3 [Co(CN) 6 ] 2 nanocubes. Thereafter, the hollow cavity of Co 3 O 4 cages was loaded with Ni nanoparticles to synthesize the final nanocatalyst (Ni@Co 3 O 4 ). Highly versatile Co 3 O 4 nanocages based nickel catalytic system has been effectively exploited for the condensation of 1,2-diamines with α-diketones for the synthesis of quinoxaline derivatives. • 3D hollow architecture of Co 3 O 4 cages permits the integration of multiple catalytic active sites. • The synthesized nanocatalyst showed high catalytic efficacy with high conversions and TON of targeted products. • The developed nanomaterial exhibits excellent durability and reusability for 6 subsequent runs. • It is anticipated thatNi@Co 3 O 4 nanocatalyst would open new avenues in the field of catalysis. Engineered nanocages have emerged at the forefront of nanomaterial investigation as they possess tremendous potential to boost key chemical processes owing to their hollow architectures that can help in achieving high reactivity. With an intention to make profitable use of their morphological features guided chemical activity, we developed dispersable Co 3 O 4 nanocages decorated with nickel nanoparticles for accessing a broad spectrum of pharmaceutically and biologically active N-heterocyclic quinoxaline nuclei using α-dicarbonyls and 1,2-diamines as precursor reagents. For designing Co 3 O 4 nanocages, we employed a simple and scalable method involving Kirkendall effect in which thermal decomposition of Co 3 [Co(CN) 6 ] 2 was carried out thereafter, nanocages were loaded with Ni nanoparticles to obtain the final Ni@Co 3 O 4 catalyst. Results revealed that Ni@Co 3 O 4 catalyst possesses immense potential to accelerate condensation of diamines and di-carbonyls in absence of any additives under mild reaction conditions. The superior catalytic efficiency has been attributed to the hollow architecture of the nanocatalyst comprising of abundant catalytic sites. This protocol exhibits several remarkable attributes such as mild reaction conditions outstanding functional group tolerance, high yield, immense durability and reusability for six subsequent runs.