Photochemical Halogen-Bonding Promoted Synthesis of Vinyl Sulfones via Vinyl and Sulfonyl Radicals

Abstract

A photochemical halogen-bonding-assisted synthesis of vinyl sulfones via radical−radical cross-coupling of vinyl bromines and sodium sulfinates is developed. This methodology offers a facile and efficient approach to various vinyl sulfones with excellent functional group tolerance under metal-, photocatalyst-, base-, and oxidant-free conditions. The reaction is also applicable for the late-stage functionalization of drug molecules and the hectogram scale. Moreover, instead of sodium sulfites being prepared, these reactions could also be conducted using sulfonyl chlorides in a one-pot method.

EDA Complex-Promoted Cascade Cyclization of Alkynes Enabling the Rapid Assembly of 3-Sulfonylindoles and Vinyl Sulfone Oxindoles

“…Combining the results from mechanistic studies and previously reported − investigations together, we propose the following mechanism (Figure ). Initially, sodium 4-methylphenylsulfinate 2a combines with 4-methyl- N -(2-(phenylethynyl)­phenyl)­benzenesulfonamide 1a to form an EDA complex I in the presence of K 2 CO 3 . , Upon light irradiation, the generated EDA complex I undergoes a SET from the donor to the acceptor, , forming an oxygen-centered radical II-1 resonating with sulfonyl radical II-2 and an N -sulfonamide radical anion III .…”

“…The recent advent of sustainable strategies based on electron donor–acceptor (EDA) complex photoactivation enables the utilization of arylsulfinate anions as convenient sulfonyl radical precursors for the synthesis of sulfone-containing compounds by direct radical–radical coupling reactions and radical involved cascade reactions. , Driven by this burgeoning EDA chemistry, Wang and Miao developed new EDA complexes using arylsulfinate anions as electron donors and isocyanides as acceptors, providing a pathway for synthesizing C6-polyfunctionalized phenanthridines . Quite recently, Shen achieved a radical cascade cyclization with alkenes, initiated by intermolecular charge transfer between arylsulfinate anions and 2-alkynylthioanisoles via the formation of an EDA complex .…”

Visible-Light-Induced Synthesis of Vinyl Sulfones via Decarboxylative Sulfonylation of Cinnamic Acids Using Sulfonylazides/p-Toluenesulfonylmethyl Isocyanide/β-Keto Sulfones

“…A stereoselective synthesis of E -vinyl sulfones has also been developed from alkynes using TsMIC as a sulfonyl source in the presence of magnetically separable nanocopper catalyst . Lately, Luo et al have demonstrated a photochemical synthesis of vinyl sulfones through halogen-bonding promoted reaction of vinyl and sulfonyl radicals …”