Photoredox-Catalyzed Radical–Radical Cross-Coupling of Sulfonyl Chlorides with Trifluoroborate Salts

Abstract

Sulfones are widely found in natural products and drug molecules. Here, we disclose a strategy for direct synthesis of sulfone compounds with diverse structures by visible-lightcatalyzed radical−radical cross-coupling of sulfonyl chlorides and trifluoroborate salts. Allyl, benzyl, vinyl, and aryl trifluoroborates can be successfully cross-coupled with (hetero)aryl and alkyl sulfonyl chlorides, respectively. This strategy features redox neutrality, good substrate generality, simple operation, and benign reaction conditions.

Synthesis of Vinyl and 1,3‐Dienyl Sulfones Enabled by Photochemical Excitation of Halogen‐Bonding Complexes

“…[6] Also in 2023, He and Guan reported another photoredox strategy for the general synthesis of sulfones (among them, vinyl sulfones), but this time employing sulfonyl chlorides and trifluoroborate salts as the reaction precursors (Scheme 1, b.2). [7] Regarding the employment of sulfinate salts as coupling partners in photochemical reactions devoted to the formation of vinyl sulfones, König and coworkers reported a photocatalytic strategy relying in the employment of Eosin Y, styrenes and sodium sulfinates (Scheme 1, b.3). [8] However, these reactions require a stoichiometric amount of an oxidant or reducing agent to enable catalytic turnover.…”

Visible-Light Induced Radical Addition–Elimination Reaction for Constructing Allylic Sulfones from Sulfonyl Chlorides and Allyl Bromides

“…This methodology has also been applied using sulfonyl hydrazides as sulfonyl radical precursors by the Zhong group in 2021 (Scheme b). The Guan group disclosed a strategy in 2023 for the synthesis of sulfone compounds by visible-light catalyzed radical–radical cross-coupling or radical addition of sulfonyl chlorides and trifluoroborate salts (such as potassium allyl trifluoroborate which needs to be prepared from allyl bromide) (Scheme c). Additionally, the insertion of sulfur dioxide via radical addition processes has also been employed for the synthesis of allylic sulfonyl compounds.…”

Visible Light‐Driven Eosin Y‐Catalyzed Suzuki‐Type Sulfonylation

“…[7] Based on environmental and practical considerations, visible light-driven photoredox catalysis has been deemed as a powerful strategy in organic synthesis. [8] Accordingly, a variety of ap-proaches for the synthesis of sulfones, including Ullmann-type sulfonylation of aryl halides with sulfinates, [9] Suzuki-type cross-coupling with sulfonyl fluorides [10] or trifluoroborate salts [11] as substrates, deaminated sulfonylation of boronic acids with sulfonamides, [12] etc., [13] have been successfully documented under visible light radiation. Although many achievements towards the visible light-driven preparation of sulfones have been obtained, transition metal catalysts (or complexes) and limitation of substrate availability are usually involved among these methods.…”