Designing novel building blocks is an overlooked strategy to improve compound quality.

One pragmatic way to improve compound quality, while enhancing and accelerating drug discovery projects, is the ability to access a high quality, novel, diverse building block collection. Here, we outline general principles that should be applied to ensure that a building block collection has the greatest impact on drug discovery projects, by discussing design principles for novel reagents and what types of reagents are popular with medicinal chemists in general. We initiated a program in 2009 to address this, which has already delivered three candidate drugs, and the success of that program provides evidence that focussing on building block design is a useful strategy for drug discovery.