Diversity-oriented synthesis articles from across Nature Portfolio

The rapid generation of molecular complexity from a given molecular scaffold is crucial to drug discovery and development. Now the chemodivergent molecular editing of indoles using fluoroalkyl carbenes has been developed to modularly access four different types of fluorine-containing N-heterocyclic compound with high molecular complexity.

Skeletal editing enables diversification of compounds not possible by applying peripheral editing strategies. Now, a catalyst-free atom-pair swap strategy for pyridine editing has been developed via one-pot sequential dearomatization, cycloaddition and rearomative retrocyclization. Benzenes and naphthalenes with precisely installed functional groups are produced, and the mild conditions enable late-stage skeletal diversification of pyridine cores.

Directing group strategies have been used extensively in C–H activation reactions but current methods rely heavily on coordination with nitrogen or oxygen atoms in molecules and have therefore been found to exhibit limited generality in asymmetric syntheses. Here, the authors report enantioselective C–H activation with unsaturated hydrocarbons directed by phosphorus centres to rapidly construct libraries of axially chiral phosphines through dynamic kinetic resolution.

The Mannich reaction is a well-established method for the synthesis of β-amino carbonyl compounds while the analogous reactions of homo-enol or its equivalents with imines or iminium ions are much less explored. Here, the authors describe a homo-Mannich reaction of cyclopropanol with imines generated via a Bischler-Napieralski reaction.

Substituted pyridines are important structural motifs present in various bioactive molecules, however their multi-functionalization remains challenging. Here, the authors report a facile approach for introducing various functional groups on the pyridine scaffold by remodeling of 3-formyl (aza)indoles/benzofurans via a ring cleavage reaction.

Natural products often provide lead scaffolds for the development of therapeutics, but complexity of their synthesis can limit the discovery of improved analogues. Pharmacophore-directed retrosynthesis aims to accelerate the building of a structure–activity relationship profile of a natural product, aiming to identifying a simplified lead.

Natural products often serve as sources of new drugs, either directly or after synthetic modification, but site-selective functionalization of complex small molecules is challenging. Now, a method has been developed that enables selective modification of a wide range of natural products by engaging a benzyne intermediate in a variety of reaction modes.

Adam Nelson and Stuart Warriner, from the University of Leeds, talk with Nature Chemistry about their work to develop viable synthetic strategies for preparing new chemical structures in parallel with the identification of desirable biological activity.

Two approaches have emerged for creating libraries of compounds for use in biological screening assays for drug discovery — fragment-based ligand design and diversity-oriented synthesis. Advocates of each approach discuss their favoured strategy.