Magnetically recoverable nano-crystalline NiFe2O4 catalyzed green and sustainable synthesis of functionalized pyrano-pyrazol, pyrano-coumarin, and 4H-chromene derivatives

Synthesis of pyrano-pyrazol, pyrano-coumarin, and 4H-chromene derivatives has been achieved by the multicomponent reaction of substituted 1,3-diketo compounds, dialkyl acetylene dicarboxylates and alkyl nitrile derivatives in presence of nano-NiFe2O4. The nano-NiFe2O4 magnetic nanoparticle was prepared by a simple and effective method and characterized by using XRD, HRTEM images, IR, and VSM studies. The green, convenient, and mild protocol provided large access to desired products in almost quantitative yield. High catalytic activity, very low catalyst loading, and high recyclability are the attractive features of the developed protocol. All reactions were easily performed and preceded with high efficiency under very mild conditions avoiding time-consuming, costly catalysts, and tedious workup and purification of process.