The conversion of arylaldehydes to 1,7-diaryl-5-hydroxyhepta-1,4,6-trien-3-ones (curcuminoids) and the mechanochemical cyclization of these products to 2,2-difluoro-4,6-bis(β-styryl)-1,3,2-dioxaborines using BF3-Et2O are described. Investigation of the cyanide ion sensing ability of the 2,2-difluoro-4,6-bis(β-styryl)-1,3,2-dioxaborines, in relation to the substituent groups on the aryl ring, showed that a hydroxy susbstituent is required, preferably