Lanthionine Peptides by <i>S</i>-Alkylation with Substituted Cyclic Sulfamidates Promoted by Activated Molecular Sieves: Effects of the Sulfamidate Structure on the Yield

Abstract

A green and efficient method for preparing lanthionine peptides by a highly chemoselective and stereochemically controlled procedure is presented. It involves an <i>S</i>-alkylation reaction, promoted by activated molecular sieves, on chiral cyclic sulfamidates, both <i>N</i>-protected and unprotected. Of note, the reaction yield was high also for cyclic sulfamidates bearing a free amine group, while other strategies failed to achieve a ring-opening nucleophilic reaction with <i>N</i>-unprotected substrates. To prove the feasibility of the procedure, the synthesis of a thioether ring B mimetic of the natural lantibiotic haloduracin β was performed.