Installation of -SO2F groups onto primary amides

Enabling Modular Click Chemistry Library through Sequential Ligations of Carboxylic Acids and Amines

High-throughput synthesis and screening of chemical libraries play pivotal roles in drug discovery. Click chemistry has emerged as a powerful strategy for constructing highly modular chemical libraries. However, the development of new click reactions and unlocking new clickable building blocks remain exceedingly challenging. Herein, we describe a double-click strategy that enables the sequential ligations of widely available carboxylic acids and amines with fluorosulfuryl isocyanate (FSO2NCO) via a modular amidation/SuFEx (sulfur-fluoride exchange) process. This method provides facile access to chemical libraries of N-fluorosulfonyl amides (RCONHSO2F) and N-acylsulfamides (RCONHSO2NR'R'') in near-quantitative yields under simple and practical conditions. The robustness and efficiency of this double click strategy is showcased by the facile construction of chemical libraries in 96-well microtiter plates from a large number of carboxylic acids and amines. Preliminary biological activity screening reveals that some compounds exhibit high antimicrobial activities against Gram-positive bacterium S. aureus and drug-resistant MRSA (MIC up to 6.25 μg ⋅ mL-1). These results provide compelling evidence for the potential application of modular click chemistry library as an enabling technology in high-throughput medicinal chemistry.

Pyridinium-Based Fluorosulfonamide Reagents Enabled Photoredox-Catalyzed Radical Fluorosulfonamidation

Sulfamoyl fluorides, as a crucial building block of SuFEx, have garnered extensive research interest due to their unique properties. However, the direct radical fluorosulfonamidation process for the synthesis of sulfamoyl fluorides has been overlooked. We herein disclosed a practical procedure for constructing a redox-active fluorosulfonamide radical reagent named fluorosulfonyl-N-pyridinium tetrafluoroborate (PNSF) from SO2F2. These reagents can facilitate a range of reactions, including the N-(fluorosulfonyl) sulfonamidation of (hetero)arenes, sequential radical stereoselective fluorosulfonamidation, and 1,2-difunctionalization of alkenes.

Transition-Metal-Free Disulfuration of Amides with Trisulfide Dioxides via Formation of Unaccessible S-S-N Bonds

Under transition-metal-free conditions, trisulfide dioxides were used as disulfurating reagents to react with a wide range of amides, affording various substituted N-disulfanyl amides in good yields. Furthermore, the gram-scale experiment has confirmed the practicability of this approach.

Synthesis of aliphatic nitriles from cyclobutanone oxime mediated by sulfuryl fluoride (SO2F2)

A SO₂F₂-mediated ring-opening cross-coupling of cyclobutanone oxime derivatives with alkenes was developed for the construction of a range of δ-olefin-containing aliphatic nitriles with (E)-configuration selectivity. This new method features wide substrate scope, mild conditions, and direct N-O activation.

Sulfur(VI) fluorides as tools in biomolecular and medicinal chemistry

Recent advances in the synthesis of sulfur(VI)-fluorides has enabled incredible growth in their application in biomolecular chemistry. This review aims to serve as a primer highlighting synthetic strategies toward a diversity of S(VI) fluorides and their application in chemical biology, bioconjugation, and medicinal chemistry.

SuFEx Activation with Ca(NTf2)2: A Unified Strategy to Access Sulfamides, Sulfamates, and Sulfonamides from S(VI) Fluorides

A method to activate sulfamoyl fluorides, fluorosulfates, and sulfonyl fluorides with calcium triflimide and DABCO for SuFEx with amines is described. The reaction was applied to a diverse set of sulfamides, sulfamates, and sulfonamides at room temperature under mild conditions. Additionally, we highlight this transformation to parallel medicinal chemistry to generate a broad array of nitrogen-based S(VI) compounds.

SO2F2-Mediated one-pot cascade process for transformation of aldehydes (RCHO) to cyanamides (RNHCN)

A simple, mild and practical cascade process for the direct conversion of aldehydes to cyanamides was developed featuring a wide substrate scope and great functional group tolerability. This method allows for transformations of readily available, inexpensive, and abundant aldehydes to highly valuable cyanamides in a pot, atom, and step-economical manner with a green nitrogen source. This protocol will serve as a robust tool for the installation of the cyanamide moiety in various complicated molecules.