To increase the chemical diversity accessible with peptoids and peptide–peptoid hybrids, N-alkylated arylsulfonamides were used to prepare side chain protected N-substituted glycines compatible with solid-phase synthesis. The described procedures give access to peptoid monomers bearing a wide variety of functional groups from commercially available amines in four straightforward steps. The prepared N-substituted N-arylsulfonylglycines were used as monomers in solid-phase synthesis to introduce relevant functionalized side chains into peptoid oligomers and peptide–peptoid hybrids.