The influence of steric factors on the formation of 99 and 100 was studied by changing the size of the substituents present in the starting aminonitriles 52 and 53 near the nitrogen atom and the quaternary carbon. The higher steric hindrance significantly lowered the yield of target sultams. In the presence of a phenyl substituent in the molecules, additional electron-withdrawing effect also decreased the efficiency of sulfonylation-cyclization sequence. The lowest yields of sultams were observed in the case of sulfonylation of N-phenyl-substituted aminonitriles for the synthesis of 99ac (38% yield) and 100bc (8% yield). In contrast, LCMS analysis revealed only trace amounts of products for the bulkiest cycloheptylidene-substituted derivatives 100cb and 100cc, which also contained N-benzyl and N-phenyl fragments, respectively. Prolonged reflux of the reaction mixture did not result in any observable reaction for N-benzyl-C-phenyl substituted aminonitrile 52bb, as well as for derivative 52bc with two phenyl substituents.