Embedded Nickel Complex on Naturally Biodegradable Gaur Gum: Catalytic Application for the Green Synthesis of 2-Amino-3-Cyano-7-Hydroxy-4H-Chromenes

This study reveals that the synthesis of a novel heterogeneous gaur gum-supported DABCO functionalized nickel(II)catalyst and its application for the synthesis of 2-amino-3-cyano-7-hydroxy-4H-chromenes. The synthesized GG@Ni(II) catalyst was characterized by FT-IR, XRD, EDX, and SEM techniques. The catalytic activities of this synthesized heterogeneous catalyst were examined in one-pot multicomponent synthesis of chromene derivatives under ultrasonic condition. A simple, benign and highly efficient ultrasound-mediated route was designed to produce chromene derivatives via one-pot, multicomponent reaction of aldehyde, malononitrile, and resorcinol at room temperature. The ultrasound-mediated synthetic route was studied here exhibits some remarkable advantages such as short reaction times, green reaction conditions, operational simplicity, high yields, and easy work-up and purification steps. In addition to this interestingly found that there was unnoticeable loss of reactivity when the catalyst was quantitatively recovered from the reaction medium and recycled up to five times.