Recent achievements and current trajectories of diversity-oriented synthesis.

For two decades, diversity-oriented synthesis (DOS) has facilitated the assembly of small-molecule libraries comprising a variety of complex molecular architectures. Here, we describe some of the recent achievements in this field, many of which promise to contribute to the development of new chemical probes and drug leads. In particular, we report progress along several avenues of bioactive discovery that leverage topographically complex compounds generated using DOS and other methods. We also discuss advances in DNA-compatible chemistry that enable syntheses of more three-dimensionally complex and diverse DNA-encoded libraries. Continual innovation in organic chemistry will be required to both expand and exploit our understanding of biological systems.