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.

InCl3-catalyzed one-pot synthesis of multi-substituted pyrano[2,3-c]pyrazole-4-carboxylic acid esters under ultrasound irradiation.

An efficient and simple procedure for the synthesis of 6-amino-5-cyano-4-phenyl-pyrano[2,3-c]pyrazole-4-carboxylic acid esters was developed via a one-pot reaction of ß-ketoester, hydrazine, benzoylacetate, and malononitrile in 50% EtOH catalyzed by InCl3 under ultrasound irradiation. This method is more economic, convenient, nontoxic, and environmentally friendly than established methods of pyranopyrazole synthesis. Target compounds were obtained in excellent yields of up to 95%.

Design, Construction, and Screening of Diversified Pyrimidine-Focused DNA-Encoded Libraries.

Pyrimidine is a ubiquitous component in natural products and approved drugs, providing an ideal modular scaffold for generating libraries with drug-like properties. DNA-encoded library technology introduces a novel library modality where each small molecule is covalently linked to a unique oligo tag. This technology offers the advantages of rapidly generating and interrogating large-scale libraries containing billions of members, substantially reducing the entry barrier to their use in both academia and the pharmaceutical industry. In this Letter, we describe the synthesis of three DNA-encoded libraries based on different functionalized pyrimidine cores featuring diversified chemoselectivity and regioselectivity. Preliminary screening of these DNA-encoded libraries against BRD4 identified compounds with nanomolar inhibition activities.