Synthesizing libraries of peptides - potentially hundreds in a single synthesizer setup - has seen a resurgence of late.  These synthetic libraries, often prepared on very small synthesis scales, are required most recently for secondary screening preliminary structure-activity relationship determinations, or neoantigen vaccine preparations.  However, optimizing the synthesis of hundreds of peptides to be made simultaneously is a very different beast when compared to optimizing the synthesis of a single peptide.

In today's post, I'll describe a strategy that can increase the overall crude purity of an entire peptide library using two different coupling chemistries.