(hetero)arylsulfones 4-(methylseleno)butyl glucosinolate (glucoselenoerucin) 6-exo-dig and 5-endo-dig cyclization BF3·OEt2 C(sp2)–SO2 bond cleavage DFT calculations DFT computations DMA FeCl3-catalyzed H2SO4 H2Se Sonogashira coupling TADF UHPLC-MS/MS X-ray analysis alkyl iodides alkyne cyclization alkynes aryl iodides benzothienobenzothiophene bismuth catalyst bismuth(III) iodide broccoli calixarene catalysis compressive strength desulfonylative functionalization diaryl diselenide diphenyl diselenide diselanes