Aliphatic Sulfonyl Fluoride Synthesis via Decarboxylative Fluorosulfonylation of Hypervalent Iodine(III) Carboxylates

Photoredox-Catalyzed Three-Component Construction of Aryl Sulfonyl Fluoride Using KHF2: Late-Stage Drug Fluorosulfonylation

Aryl sulfonyl fluorides are prominently featured in organic synthesis and medicinal chemistry. Herein, a metal-free photoredox-catalyzed three-component assembly of aryl sulfonyl fluoride via aryl sulfonyl ammonium salt intermediate has been reported. A variety of structurally diverse aryl sulfonyl fluorides were synthesized rapidly from dibenzothiophenium (DBT) salts under mild conditions by using KHF2 as the fluorine source. Notably, this methodology can be employed as an efficient and sustainable approach for late-stage drug fluorosulfonylation. Good yields and broad functionality tolerance were the features of this methodology. Moreover, the derivatization of aryl sulfonyl fluoride molecules was also demonstrated to showcase its synthetic utility.

Copper-Catalyzed Oxyfluorosulfonylation of β,γ-Unsaturated Oximes with Sulfur Dioxide and Selectfluor for Isoxazoline-Functionalized Aliphatic Sulfonyl Fluorides

In this report, we describe a copper-catalyzed cascade reaction involving oxygen radical-induced cyclization/SO2 insertion/fluorination of β,γ-unsaturated oximes with sulfur dioxide and Selectfluor under mild conditions for the synthesis of isoxazoline-functionalized aliphatic sulfonyl fluorides. The synthetic potential of these compounds has been evaluated through diverse SuFEx reactions.

Copper-Catalyzed, Interrupted Remote Fluoromethylthiolation of Unactivated C(sp3)-H Bonds

An efficient copper-catalyzed selective fluoromethylthiolation of an inert δ-C(sp3)-H bond in sulfonamides was reported. In the presence of a copper catalyst and PhSO2SRf, the radical generated through 1,5-hydrogen atom transfer (HAT) was sufficiently trapped by PhSO2SRf, instead of copper, which was prevalent in metal-catalyzed radical-relay processes, incorporating a fluoromethylthio group into molecules. The general substrate scope and mild conditions endowed the method with wide potential applications in pharmaceuticals and agrochemicals.

Radical Hydro-Fluorosulfonylation of Propargylic Alcohols via Electron Donor-Acceptor Photoactivation

A radical hydro-fluorosulfonylation of propargyl alcohols with FSO2Cl is presented based on the photoactivation of the electron donor-acceptor (EDA) complex. The reaction avoids the requirement for photocatalysts, bases, hydrogen donor reagents, any other additives, and harsh conditions, enabling the facile synthesis of various functionalized γ-hydroxy (E)-alkenylsulfonyl fluorides. These multifunctional sulfonyl fluorides can be further diversified, providing access to various privileged molecules of biological relevance.