A Vending Machine for Drug-like Molecules – Automated Synthesis of Virtual Screening Hits

19 September 2022, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


As a result of high false positive rates in virtual screening campaigns, prospective hits must be synthesised for validation. When done manually, this is a time consuming and laborious process. Large “on-demand’ virtual libraries ( > 7 x 1012 members), suitable for preparation using capsule-based automated synthesis and commercial building blocks, were evaluated to determine their structural novelty. One sub-library, constructed from iSnAP capsules, aldehydes and amines, contains unique scaffolds with drug-like physicochemical properties. Virtual screening hits from this iSnAP library were prepared in an automated fashion for evaluation against Aedes Aegypti and Phytophthora Infestans. In comparison to manual workflows, this approach provided a 10-fold improvement in user efficiency. A streamlined method of relative stereochemical assignment was also devised to augment the rapid synthesis. User efficiency was further improved to 100-fold by downscaling and parallelising capsule-based chemistry on 96-well plates equipped with filter bases. This work demonstrates that automated synthesis consoles can enable the rapid and reliable preparation of attractive virtual screening hits from large virtual libraries.


organic chemistry
virtual screengin
on-demand synthesis
drug discovery

Supplementary materials

Supporting Information
Virtual library enumeration, synthesis, characterisation, and stereochemical determination.


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