<i>N</i>‑Substituted Iminothiolane\n(NIT): A Promising Strategy for Protecting Lysine Side Chains for\nSolid-Phase Peptide Chemistry

In this study, we introduce <i>N</i>-substituted\niminothiolane\n(NIT) as a robust protecting group for lysine side chains. NIT is\ncompatible with Fmoc-SPPS and can be efficiently removed under mild\nnucleophilic conditions. Notably, NIT offers enhanced hydrophilicity\ncompared to traditional orthogonal lysine-protecting groups and does\nnot undergo intramolecular migration. Additionally, the synthesis\nof NIT in aqueous media highlights its eco-friendly nature, positioning\nit as a promising alternative to protect lysine side chains.