DNA Barcoding a Complete Matrix of Stereoisomeric Small Molecules

The syntheses of DNA-encoded libraries (DELs) cannot fully exploit the capabilities of modern synthetic organic chemistry, so it is challenging to incorporate stereochemical diversity and topographic complexity into DEL design. Here, we describe the design, construction, and validation of a library of 107,616 DNA-barcoded chiral 2,3-disubsituted azetidines and pyrrolidines. We used stereospecific C–H arylation chemistry to furnish complex scaffolds primed for DEL synthesis, and we developed an improved on-DNA Suzuki reaction to maximize library quality. Tanimoto multi-fusion similarity analysis, among other techniques, quantified the impact of synthetic decisions on small-molecule physicochemical properties and library diversity. Validation screens against horseradish peroxidase and carbonic anhydrase IX—analyzed by a novel statistical framework—confirmed the success of the synthesis and screening procedures. These results demonstrate that diverse collections of structurally complex DNA-barcoded compounds may be synthesized without the development of novel DNA-compatible chemistry.