Water-mediated radical C-H tosylation of alkenes with tosyl cyanide

Metal-free iodosulfonylation of alkynes to access (E)-β-iodovinyl sulfones in water

With the escalating concerns regarding environmental pollution caused by organic solvents, chemists are increasingly focusing on conducting organic reactions in water, nature's chosen solvent for chemical synthesis. Herein, the development of metal-free iodosulfonylation of alkynes with p-toluenesulfonyl cyanide and NIS for the synthesis of (E)-β-iodovinyl sulfones in water is reported. This reaction gives the desired products in good to excellent yields with high regio- and stereoselectivity by using water as a green solvent at room temperature. This reaction could be readily scaled up, and synthetic application was also studied.

Radical 1,3-Hydrosulfonylation of Vinyldiazo Compounds with Sulfinyl Sulfones

Sulfinyl sulfones, as high-valence sulfurization reagents, are widely used to assemble sulfur sources on carbon skeletons, such as one-, two-, and four-carbon synthons, to access organosulfur compounds. However, their reaction with three-carbon synthons has remained a mystery until now. We report here a radical 1,3-hydrosulfonylation of vinyldiazo compounds with sulfinyl sulfones. This reaction not only represents the first example of the reaction of sulfinyl sulfones with three-carbon synthons but also opens up the application of vinyldiazo compounds in radical monofunctionalization.

C(sp2)-Arylsulfones Directly from Arylsulfonyl Chlorides with Boronic Acids by Photoactivation of Boosted EDA Complexes

Directly with arylsulfonyl chlorides, a green and efficient deborylativesulfonylation of aryl(alkenyl)boronic acids has been developed to access both diarylsulfones and vinylarylsulfones in moderate to excellent yields at room temperature under visible-light irradiation. This protocol features broad C(sp2)-arylsulfone applicability, simple operation, accessibility of raw materials and ease of scale-up. The key to the success of this photoredox transformation is introducing catalytic amounts of additives, naphthalen-2-ols, thus boosting the formed electron donor-acceptor (EDA) complexes, which can dramatically improve not only the reaction efficiency but also the selectivity. This strategy was inspired and derived from specific substrates, representing a rare paradigm of how to exploit a more general reaction system. Moreover, extensive control experiments provide insights into the proposed mechanism.

Catalyst-Free Visible Light-Driven Hydrosulfonylation of Alkenes and Alkynes with Sulfonyl Chlorides in Water

A convenient and sustainable method for synthesizing sulfonyl-containing compounds through a catalyst-free aqueous-phase hydrosulfonylation of alkenes and alkynes with sulfonyl chlorides under visible light irradiation is presented. Unactivated alkenes, electron-deficient alkenes, alkyl and aryl alkynes can be hydrosulfonylated with various sulfonyl chlorides at room temperature with excellent yields and geometric selectivities by using tris(trimethylsilyl)silane as a hydrogen atom donor and silyl radical precursor to activate sulfonyl chlorides. Mechanistic studies revealed that the photolysis of tris(trimethylsilyl)silane in aqueous solution to produce silyl radical is crucial for the success of this reaction.

Divergent Reaction of Alkynes and TsCN: Synthesis of β-Sulfinyl Alkenylsulfones and (E)-Vinyl Sulfones

An efficient and high-selectivity approach for the divergent synthesis of β-sulfinyl alkenylsulfones and (E)-vinyl sulfones from alkynes and TsCN is described. A series of disulfurized products were constructed under mild conditions in the absence of transition metals. This transformation featured excellent regio- and stereoselectivity, good functional group compatibility, and broad substrate scope. The copper(I)-catalyzed sulfonation of alkynes with TsCN that affords (E)-vinyl sulfones in good to excellent yields was also developed.

Photo-induced radical transformations of tosyl cyanide

Tosyl cyanide is a commonly used reagent for cyanation and sulfonylation in organic synthesis and pharmaceutical chemistry. The photocatalytic transformations of tosyl cyanide are generally conducted under mild conditions. This minireview summarizes the recent progress of radical-involved transformations of tosyl cyanide via photo-induced cyanation or sulfonylcyanation.