|
چکیده
|
Schiff base transition metal complexes have been widely used as homogenous or heterogeneous catalysts in various organic reactions [1]. Homogeneous catalysts exhibit higher catalytic activities than their heterogeneous counterparts due to solubility ofhomogeneous catalysts in reaction media in whichsolubility increases catalytic site accessibility for the substrate.These systems have several drawbacks as the difficulty of catalyst recycling [2].To overcome this problem, Many attempts have been done for immobilization of homogeneous catalysts on a solid supports.This is known as “heterogenization of homogeneous catalytic systems”. These third generation catalysts not only preserve the activity and selectivity of homogeneous catalysts but also allow facile recovery and reuse of the catalyst akin to heterogeneous catalysts [3,4].Heterogeneous base catalyzed organic synthesis is a promising field of research with potential application in pharmaceuticals and related fine chemical industries [5,6]. In this work, we functionalized magnetite nanoparticles with amine groups and then incorporate a molybdenum Schiff base complex with anchoring method to obtain a heterogeneous molybdenum catalyst.The magnetic molybdenum nano-catalyst could be used as a heterogeneous catalyst with high catalytic activity in one-pot and green synthesis of 2-amino-4H-benzo[h]chromenes via three-component condensation reaction of different aromatic aldehydes, malononitrile and 1-naphthol under solvent free conditions. The benefits of this process are short reaction times, easy isolation and excellent yields of the desired products.
|