Introduction of N,N'-disulfonylhydrazines as new sulfonylating reagents for highly efficient synthesis of (E)-β-iodovinyl arenesulfones under mild conditions

Visible Light-Induced Photocatalyst-Free Diastereoselective Iodosulfonylation of Cyclopropenes in Water

This study presents a greener approach to the visible-light-induced micellar-catalyzed diastereoselective iodosulfonylation of cyclopropenes in a water medium. Remarkably, this process operates without a photocatalyst. Instead, it utilizes an electron-donor-acceptor complex formed between sulfonyl chloride and sodium iodide. This method is highly efficient and broadly applicable for both aromatic and aliphatic sulfonyl chlorides. Furthermore, this protocol enables the transformation of iodosulfonated cyclopropanes into sulfonated cyclopropenes, highlighting its substantial value as a versatile and powerful tool in synthetic chemistry.

Copper-Catalyzed Radical Sulfonylation: Divergent Construction of C(sp3)-Sulfonyl Bonds with Sulfonylhydrazones

Sulfonylhydrazones have been proven to be versatile synthetic intermediates in a panel of transformations. However, radical sulfonylation with sulfonylhydrazone as sulfonyl radical source is relatively rare. Here, we found that sulfonylhydrazone can serve as a new sulfonyl radical precursor to couple various partners such as arylacetic acids, ene-yne-ketones, and para-quinone methides under copper catalysis and microwave irradiation. The reactions of sulfonyl radicals have been successively developed to enable the divergent synthesis of C(sp3)-sulfonyl bonds. In addition, when alkynes and alkenes are used as radical receptors, this method can also promote the formation of C(sp2)-sulfonyl bonds. This finding suggests that sulfonylhydrazone could be regarded as a potentially useful sulfonyl radical in sulfone synthesis.

Recent Advancements in Metal-Catalyst-Free Multicomponent Radical Sulfonylation of Alkynes

Vinyl sulfones are crucial building blocks in synthetic chemistry and core structural units of pharmaceutically active molecules, thus extensive investigations have been conducted on the construction of these skeletons. In contrast to the classical synthetic approaches, the radical sulfonylation of alkynes for producing vinyl sulfones has garnered considerable interest because of its mild conditions and high efficiency. Radical sulfonation of alkynes typically begins with the sulfonyl radical attacking the alkynes, followed by further functionalization. Moreover, the association of metal-catalyst-free systems with multicomponent reactions (MCRs) offers an environmentally friendly pathway for efficiently constructing complex scaffolds from readily available partners. However, there is no comprehensive review summarizing the advancements in metal-catalyst-free multicomponent radical sulfonylation of alkynes. Hence, we provide a categorical overview based on the objects of sulfonylation of alkynes (hydrosulfonylation, carbosulfonylation, aminosulfonylation, oxysulfonylation, sulfosulfonylation, selenosulfonylation, and iodosulfonylation), along with interpretations of the reaction mechanisms.

Recent trends in the synthesis and applications of β-iodovinyl sulfones: a decade of progress

Direct vicinal difunctionalization of π-systems has emerged as a powerful platform for constructing multiple bonds in a single synthetic operation using simple chemical feedstocks. Over the past decade, there has been exponential growth in the direct construction of successive C-S and C-I bonds using a wide variety of sulfonyl and iodide reactants through 1,2-iodosulfonylation of alkynes in a regio- and stereo-selective manner. In this review, we mainly focus on the recent developments in the preparation of β-iodovinyl sulfones and their practical applications in organic synthesis. The most promising photoredox and electrochemical transformations for synthesizing β-iodovinyl sulfones are also reviewed. The multifunctional β-iodovinyl sulfones have recently been burgeoning as versatile synthetic precursors due to the combination of vinyl iodide and vinyl sulfone moieties, essential building blocks for diverse synthetic manipulations. We hereby present the chemistry of β-iodovinyl sulfones, which can be classified into numerous sections based on the sulfonyl surrogates, and potential synthetic approaches are systematically outlined.

Iodosulfonylation of Alkynes under Ultrasound Irradiation

(E)-β-Iodo vinylsulfones are synthesized under ultrasound irradiation using alkynes, sulfonyl hydrazides, potassium iodide and hydrogen peroxide. The key features of this protocol are the speed and efficiency of the reactions, which afford good to excellent yields of the desired products by employing ultrasound as the driving force. Mechanistic studies reveal that a sulfonyl radical intermediate is generated via sulfonyl iodide homolysis.

Direct halosulfonylation of alkynes: an overview

The difunctionalization reactions of easily available and inexpensive alkynes have emerged as a reliable, powerful, and step-economical approach for the construction of highly substituted complex alkenes in a one-pot manner, without the need for isolation of intermediates. A wide variety of transformations based on this concept have been successfully achieved for the preparation of synthetically and biologically important β-halovinyl sulfone scaffolds. In this Review, we summarize the recent advances and developments in this field and present a comprehensive overview of halosulfonylation of alkyne substrates with emphasis on the mechanistic features of the reactions.