Late-Stage Functionalization by Chan-Lam Amination: Rapid Access to Potent and Selective Integrin Inhibitors

Late-stage modification of bioactive compounds: Improving druggability through efficient molecular editing

Synthetic chemistry plays an indispensable role in drug discovery, contributing to hit compounds identification, lead compounds optimization, candidate drugs preparation, and so on. As Nobel Prize laureate James Black emphasized, "the most fruitful basis for the discovery of a new drug is to start with an old drug"1. Late-stage modification or functionalization of drugs, natural products and bioactive compounds have garnered significant interest due to its ability to introduce diverse elements into bioactive compounds promptly. Such modifications alter the chemical space and physiochemical properties of these compounds, ultimately influencing their potency and druggability. To enrich a toolbox of chemical modification methods for drug discovery, this review focuses on the incorporation of halogen, oxygen, and nitrogen-the ubiquitous elements in pharmacophore components of the marketed drugs-through late-stage modification in recent two decades, and discusses the state and challenges faced in these fields. We also emphasize that increasing cooperation between chemists and pharmacists may be conducive to the rapid discovery of new activities of the functionalized molecules. Ultimately, we hope this review would serve as a valuable resource, facilitating the application of late-stage modification in the construction of novel molecules and inspiring innovative concepts for designing and building new drugs.

Late-stage functionalization of 5-nitrofurans derivatives and their antibacterial activities

Structure modification of drugs is a reliable way to optimize lead compounds, among which the most striking and direct method is late-stage functionalization (LSF). Here, we employed the Cu-catalyzed C-H LSF to modify 5-nitrofuran drugs. A series of modifications have been carried out including hydroxylation, methylation, azidination, cyanation, arylation, etc. Antibacterial activities of all compounds in vitro were measured. The results showed that compound 1 and compound 18 were the most active among all compounds. Meanwhile, the cell cytotoxicity assays of potent compounds 1, 3, 4, 5 & 18 and the parent drug FZD were conducted.

A base-free Chan–Lam reaction catalyzed by an easily assembled Cu(II)-carboxylate metal-organic framework

A new copper(II) metal-organic framework is constructed as a sustainable copper heterogeneous catalyst. Cu-DPTCA, with high catalytic activity, can effectively promote the Chan–Lam coupling reaction of arylboronic acids and amines without adding any base or additive.

Molecular Simulation of αvβ6 Integrin Inhibitors

The urgent need for new treatments for the chronic lung disease idiopathic pulmonary fibrosis (IPF) motivates research into antagonists of the RGD binding integrin αvβ6, a protein linked to the initiation and progression of the disease. Molecular dynamics (MD) simulations of αvβ6 in complex with its natural ligand, pro-TGF-β1, show the persistence over time of a bidentate Arg-Asp ligand-receptor interaction and a metal chelate interaction between an aspartate on the ligand and an Mg²⁺ ion in the active site. This is typical of RGD binding ligands. Additional binding site interactions, which are not observed in the static crystal structure, are also identified. We investigate an RGD mimetic, which serves as a framework for a series of potential αvβ6 antagonists. The scaffold includes a derivative of the widely utilized 1,8-naphthyridine moiety, for which we present force field parameters, to enable MD and relative free energy perturbation (FEP) simulations. The MD simulations highlight the importance of hydrogen bonding and cation-π interactions. The FEP calculations predict relative binding affinities, within 1.5 kcal mol^-1, on average, of experiments.

Imidazole-directed fabrication of three polyoxovanadate-based copper frameworks as efficient catalysts for constructing C–N bonds

Three polyoxovanadate-based copper frameworks with 3D, 2D and 1D networks have been developed and they displayed efficient heterogeneous catalytic activities in the Chan-Lam reaction.

Iridium-catalysed C–H borylation of β-aryl-aminopropionic acids

Iridium-catalysed C–H borylation of β-aryl-aminopropionic acid derivatives gives 3,5-functionalised protected β-aryl-aminopropionic acid boronates. One-pot borylation–functionalisation provides diverse building blocks for medicinal chemistry.