Microwave Assisted Multi-component Synthesis of 4Hchromene Derivatives by Nano-coconut Shell-BF3 as a New Heterogeneous Catalyst

Microwave assisted reactions have gained considerable attention, due to versatility and reduction ofsolvent and reaction time. The reaction of a nano-coconut shell and boron tri-fluoride in diethylether solvent resulted in preparation of nano-coconut shell-BF3 as a catalyst. The nano-coconutshell-BF3 catalyst has been characterized by fourier transform infrared spectroscopy (FT-IR), fieldemission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM).Nano-coconut shell-BF3 has been applied as a new heterogeneous catalyst for synthesis of 4Hchromenederivatives from the simple one-pot reaction between aryl aldehydes, cyclic 1,3-diketoneand, malononitrile under microwave reaction. Cleanliness, simple methodology, short time, andexcellent yields of products are some advantages of this method.