Effect of the Helical Tether of a Resin-Supported Peptide Catalyst for Friedel-Crafts-Type Alkylation in Water

A detailed investigation of the helical part of the resin-supported peptide catalyst possessing a turn motif and helical unit was conducted to clarify the structure-activity relationship. The peptide catalyst with an a- or 310-helical tether was effective for an enantioselective FriedelCrafts-type alkylation in water. From the spectral analysis of the peptide with an optimum sequence, it was demonstrated that the helical moiety of the peptide catalyst played a role for stabilizing a terminal turn structure.