In small-molecule drug discovery, the value of a molecular building block depends not only on whether its structure is novel, but also on whether it can be effectively introduced into target molecules and provide well-defined variables for structural optimization.
A recurring tension in medicinal design is this: you want stronger binding, better solubility/exposure, more controllable metabolism and selectivity—without tearing down and rebuilding the entire scaffold. Over the past decade-plus, “small, polar, sp³-rich” four-membered rings—oxetanes and ...