FSO2N3-Mediated On-DNA Diazo-Transfer Chemistry

Abstract

DNA-encoded library (DEL) is a powerful hit selection technique in both basic science and innovative drug discovery. In this study, we report a robust and straightforward DNA-compatible diazo-transfer reaction utilizing FSO₂N₃ as the diazo-transfer reagent in solution. This reaction demonstrates high conversions and facile operation while being metal-free and maintaining high levels of DNA fidelity. It is also compatible with a wide range of substrates, allowing for convenient access to both aliphatic and aromatic amines. Consequently, it will further enrich the DEL chemistry toolbox.

Figure 1

(a) ISA-enabled on-DNA diazo-transfer. Single-stranded DNA (ssDNA) was used in condition i and double-stranded DNA (dsDNA) was used in condition ii. (b) This work: Fluorosulfuryl azide (FSO₂N₃)-enabled metal-free on-DNA diazo-transfer.

Scheme 1. Substrate Scope of DNA-Conjugated Amines

Standard conditions: A (2 nm), B (12.5 μL, 80 mM in MTBE) in 50 μL MTBE-DMSO-NaHCO₃ (0.1 M, pH 8.3) (1:1:2) cosolvent, rt, 2 h. Unless otherwise noted dsDNA was used in the experiment. ssDNA was used. The conversion of A was analyzed by UPLC-MS.

Figure 2

Investigation of the integrity of the DNA tag under the established on-DNA diazo-transfer reaction. (a) Enzymatic DNA ligation of on-DNA reaction final product L-C16 with a 50 bp primer. (b) Gel analysis of the DNA ligation product L-C16 (a, b, c, d, e, and f indicates enzymatic DNA ligation using on-DNA reaction final product L-C16 or headpiece DNA with a molar gradient of the 50 bp primer. a, headpiece DNA/primer (1:1). b, L-C16/primer (0.8:1). c, L-C16/ primer (0.9:1). d, L-C16/primer (1:1). e, L-C16/primer (1.1:1). f, L-C16/primer (1.2:1)). (c) Analysis of the amplifiable materials of an in-house DEL (10⁷) incubated under the standard on-DNA diazo-transfer reaction condition. The positive control used the reaction condition of CuAAC. (d) The application potential of the on-DNA diazo-transfer reaction in the DEL setting.