Structural tuning enables piezochromic and photochemical properties in N -aryl-β-enaminones.

An efficient synthesis of N -aryl-β-enaminones via Et 3 N-mediated, one-pot three-component reaction of 4-hydroxycoumarin/dimedone, β-nitrostyrene/2-(2-nitrovinyl)thiophene, and arylamine in toluene under refluxed conditions is herein presented. Some prepared compounds were found to exhibit piezochromic properties. The XRD and SEM measurements of the piezochromic compound showed substantial crystal packing and morphology changes before and after grinding. Further, one prepared compound was found to be light-sensitive and can be converted to a furo[3,2- b ]pyridin-2(4 H )-one derivative upon UV irradiation. A plausible mechanism for this photochemical reaction was proposed.