DNA Barcoding a Complete Matrix of Stereoisomeric Small Molecules

<p></p><p>It is challenging to incorporate stereochemical diversity and topographic complexity into DNA-encoded libraries (DELs) because DEL syntheses cannot fully exploit the capabilities of modern synthetic organic chemistry. Here, we describe the design, construction, and validation of DOS-DEL-1, 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. We then studied both the structural diversity of the library and the physicochemical properties of individual compounds using Tanimoto multi-fusion similarity analysis, among other techniques. These analyses revealed not only that most DOS-DEL-1 members have “drug-like” properties, but also that the library more closely resembles compound collections derived from diversity synthesis than those from other sources (<i>e.g.</i>, commercial vendors). Finally, we performed validation screens against horseradish peroxidase and carbonic anhydrase IX, and we developed a novel, Poisson-based statistical framework to analyze the results. A set of assay positives were successfully translated into potent carbonic anhydrase inhibitors (IC<sub>50</sub> = 20.1–68.7 nM), which confirmed the success of the synthesis and screening procedures. These results establish a strategy to synthesize DELs with scaffold-based stereochemical diversity and complexity that does not require the development of novel DNA-compatible chemistry.</p><p></p>