Synthesis and Biological Properties of Quaternary Cyclobutane
The[2+2]cycloaddition reaction under light irradiation can efficiently synthesize complex compounds,which is one of the most direct and effective methods to obtain quaternary compounds.Herein,we successfully synthesized a acrylonitrile compound 2 and its[2+2]cyclized quaternary cy-clobutane derivative 3,and also studied their structures,thermal stabilities,and biological activities.The results indicate that[2+2]cyclization reaction reduces molecular conjugation.Compounds 2 and 3 have the satisfied thermal stabilities and are in a crystalline state at room temperature.The fluores-cence quenching mechanism of compounds 2 and 3 and calf thymus ctDNA is single quenching,and the cyclized quaternary cyclobutane derivative 3 has an inhibitory effect on oral squamous cell carcino-ma cells(OSCC),with a half inhibitory concentration(IC50)of 1.944 mol·L-1.