Synthesis and photophysical properties of benzo[c]thiophene, p-phenylene-, triphenylamine-, and pyrene-based vinylenes

An efficient synthesis of benzo[c]thiophenyl/p-phenylenyl/pyrenyl phosphonate esters has been achieved using ZnBr₂-catalyzed Michaelis–Arbuzov reaction of corresponding benzyl alcohol/bromides at room temperature. Horner–Wadsworth–Emmons reaction of the phosphonate esters with aryl/heteroaryl aldehydes in the presence of t-BuOK furnished the vinylenes in good yields. The absorption and emission characteristics of the synthesized vinylenes were also reported.