Nano catalytic synthesis of flavanone phosphonates using domino Knoevenagel-phospha-Michael route

Novel derivatives of diethyl (4-oxo-2-phenylchroman-3-yl) methyl phosphonate have been synthesized under optimal conditions using domino-Knoevenagel-phospha-Michael reaction catalyzed by nano-zinc oxide. The combination of recovery and reusability of catalyst, simple and applicable approach, good reaction time and good yields of products make this method as a suitable route for this purpose. The structures of the products were determined by FT-IR, ¹H-, ¹³C- and ³¹P- Nuclear Magnetic Resonance spectroscopies, and elemental analysis.