Rolling Loop Scan: An approach featuring ring-closing methathesis for generating libraries of peptides with molecular shapes mimicking bioactive comformations or local folding of peptides and proteins

Libraries of loop-containing peptides (such as the one shown schematically) can be prepared from bis-N-alkylated peptides by ring-closing metathesis. In a general solid-phase procedure the peptides are accessible by site-specific N-alkylation. Since the amino acid side chains are not involved in cyclization, they remain available for interaction with, for example, a receptor.