The Application of Encapsulated Trinuclear Cobalt Cluster Complex in Y Zeolite in the One-Pot Multi-Component Synthesis of Spiro Indoline Derivatives

A trinuclear cobalt cluster complex was prepared into the nanocages of dealuminated Y zeolite ([Co-3(O)(CH3COO)(6)(py)(3)]-DAZY) and characterized by XRD, FT-IR, EDS, FE-SEM, AAS and BET-BJH analyses. The elemental content of Cobalt in [Co-3(O)(CH3COO)(6)(py)(3)]-DAZY was estimated to be about 5.5 mg/g support on the basis of atomic absorption spectroscopy. The catalytic activity of [Co-3(O)(CH3COO)(6)(py)(3)]-DAZY was evaluated in the synthesis of tri series of spiro indoline derivatives in a library synthesis via the condensation of isatins, malononitrile or ethylcyano acetate, and active methylene compounds (4-hydroxycoumarine, dimedone and pyrazoline-5-one). Corresponding products were obtained in good to excellent yields. Short reaction time, high yield of product, structural diversity of products, absence of organic solvents and the use of water as a green solvent, non-toxicity, stability and reusability of the catalyst are noteworthy advantages of the current work.