Several cyclopropyl-containing photoacid generators (PAGs) were synthesized in order to reduce absorbance at 193 nm and induce the photobleaching effect. From the GC–mass experiment, cleavage of S–C(cyclopropyl) which is more preferential than that of S–C(phenyl) results in photobleaching effect. The resist containing cyclopropyldiphenylsulfonium triflate gave better resolution than the resist containing the conventional PAG, triphenylsulfonium triflate.
Cyclopropyldiphenylsulfonium salt, a famous ylide precursor previously extensively employed in the preparation of cyclic compounds, has been successfully utilized as an efficient allylation reagent in this work. The copper-catalyzed reactions of cyclopropyldiphenylsulfonium trifluoromethanesulfonate with amines in the presence of an appropriate ligand provided the N-allylated products in good yields. Aliphatic/aromatic