Synthesis of 5-substituted tetrazoles via DNA-conjugated nitrile

Catalytic Tetrazole Synthesis via [3+2] Cycloaddition of NaN3 to Organonitriles Promoted by Co(II)-complex: Isolation and Characterization of a Co(II)-diazido Intermediate

The [3+2] cycloaddition of sodium azide to nitriles to give 5-substituted 1H-tetrazoles is efficiently catalyzed by a Cobalt(II) complex (1) with a tetradentate ligand N,N-bis(pyridin-2-ylmethyl)quinolin-8-amine. Detailed mechanistic investigation shows the intermediacy of the cobalt(II) diazido complex (2), which has been isolated and structurally characterized. Complex 2 also shows good catalytic activity for the synthesis of 5-substituted 1H-tetrazoles. These are the first examples of cobalt complexes used for the [3+2] cycloaddition reaction for the synthesis of 1H-tetrazoles under homogeneous conditions.

DNA-Compatible Cyanomethylation of (Hetero)aryl Halides or Triflates under a Tandem Reaction for DNA-Encoded Library Synthesis

A DNA-compatible reaction has been developed for the cyanomethylation of (hetero)aryl halides or triflates via a tandem process involving palladium-mediated Suzuki-Miyaura coupling and base-promoted isoxazole fragmentation. This one-pot protocol employs easily accessible starting materials, exhibits a wide substrate scope, and results in no significant DNA damage. Additionally, the resulting (hetero)arylacetonitriles can be converted into the corresponding carboxylic acids, which may be utilized for the synthesis of DNA-encoded chemical libraries.

Privileged heterocycles for DNA-encoded library design and hit-to-lead optimization

It is well known that heterocyclic compounds play a key role in improving drug activity, target selectivity, physicochemical properties as well as reducing toxicity. In this review, we summarized the representative heterocyclic structures involved in hit compounds which were obtained from DNA-encoded library from 2013 to 2021. In some examples, the state of the art in heterocycle-based DEL synthesis and hit-to-lead optimization are highlighted. We hope that more and more novel heterocycle-based DEL toolboxes and in-depth pharmaceutical research on these lead compounds can be developed to accelerate the discovery of new drugs.

On-DNA Synthesis of Functionalized 4H-Pyran Scaffolds for Focused DNA-Encoded Chemical Libraries

The functionalized 4H-pyran scaffold has aroused synthetic attention because it is widely found in many interesting pharmacologically relevant compounds. We here disclose its incorporation into DNA-encoded chemical libraries, combining this scaffold with the merits of scaffold architecture in drug design. Under the optimized DNA-compatible conditions, functionalized 4H-pyrans were efficiently formed with a broad substrate scope. Among the 4H-pyrans formed, the axial structure features rotational restriction, and the spirocyclic structure provides rigidity and three-dimensionality. These efforts open the door for the construction of DNA-encoded chemical libraries with more consideration for this structural architecture.

Vinyl azide as a synthon for DNA-compatible divergent transformations into N-heterocycles

Inspired by diversity-oriented synthesis, we have developed a series of DNA-compatible transformations utilizing on-DNA vinyl azide as a synthon to forge divergent N-heterocyclic scaffolds. Polysubstituted imidazoles and isoquinolines were efficiently obtained with moderate-to-excellent conversions. Besides, the "one-pot" strategy to prepare in-house on-DNA vinyl azides afforded synthons readily. Results from substrate scope exploration and enzymatic ligation further demonstrate the feasibility of these N-heterocycle syntheses in DNA-encoded chemical library construction.

Development of on-DNA vinyl sulfone synthesis for DNA-encoded chemical libraries

We present the development of an efficient synthetic route to generate a DNA-compatible vinyl sulfone functional group, and the subsequent chemical transformations demonstrated the feasibility of our method in DEL construction.

A General Set of DNA-Compatible Reactions for Preparing DNA-Tagged Multisubstituted Pyrroles

DNA-encoded library (DEL) technology provided a powerful screening platform for identifying potential bioactive small molecules with high affinity to biologically interesting targets. Essential to a successful DEL campaign are the drug-like small molecular moieties of DNA-encoded libraries with expanded chemical space. Our laboratory has been working on developing and producing novel DNA-encoded libraries that complement current reported DELs. Herein, we demonstrated a general set of DNA-compatible reactions that enable the preparation of pyrrole-based DNA-encoded libraries in which the DNA tags are linked to the N position of the pyrrole central core. Further diversification could be rapidly incorporated into the pyrrole scaffold by robust iodination and Suzuki coupling reactions.

Design and construction of a stereochemically diverse piperazine-based DNA-encoded chemical library

Here we report the successful construction of a novel, stereochemically diverse DNA-Encoded Chemical Library (DECL) by utilizing 24 enantiomerically pure trifunctional 2, 6- di-substituted piperazines as central cores. We introduce the concept of positional diversity by placing the DNA attachment at either of two possible sites on the piperazine scaffold. Using a wide range of building blocks, a diverse library of 77 million compounds was produced. Cheminformatic analysis demonstrates that this library occupies a wide swath of chemical space, and that the piperazine scaffolds confers different shape diversity compared to the commonly used triazine core.

DNA-encoded chemistry technology yields expedient access to SARS-CoV-2 Mpro inhibitors

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has killed more than 4 million humans globally, but there is no bona fide Food and Drug Administration-approved drug-like molecule to impede the COVID-19 pandemic. The sluggish pace of traditional therapeutic discovery is poorly suited to producing targeted treatments against rapidly evolving viruses. Here, we used an affinity-based screen of 4 billion DNA-encoded molecules en masse to identify a potent class of virus-specific inhibitors of the SARS-CoV-2 main protease (M^pro) without extensive and time-consuming medicinal chemistry. CDD-1714, the initial three-building-block screening hit (molecular weight [MW] = 542.5 g/mol), was a potent inhibitor (inhibition constant [K _i] = 20 nM). CDD-1713, a smaller two-building-block analog (MW = 353.3 g/mol) of CDD-1714, is a reversible covalent inhibitor of M^pro (K _i = 45 nM) that binds in the protease pocket, has specificity over human proteases, and shows in vitro efficacy in a SARS-CoV-2 infectivity model. Subsequently, key regions of CDD-1713 that were necessary for inhibitory activity were identified and a potent (K _i = 37 nM), smaller (MW = 323.4 g/mol), and metabolically more stable analog (CDD-1976) was generated. Thus, screening of DNA-encoded chemical libraries can accelerate the discovery of efficacious drug-like inhibitors of emerging viral disease targets.