Efficient sulfonylation of ketones with sodium sulfinates for the synthesis of β-keto sulfones

Transition Metal Catalyst-Free C-3 Sulfonylmethylation of Imidazo[1,2-a]pyridines with Glyoxylic Acid and Sodium Sulfinates in Water

Herein, we describe an efficient and benign protocol for direct C-3 sulfonylmethylation of imidazo[1,2-a]pyridines with glyoxylic acid and sodium sulfinates. Various sulfonylmethylated imidazo[1,2-a]pyridines were synthesized in water under transition metal catalyst-free conditions. This multicomponent reaction featured available substrates, good functional group tolerance, moderate to excellent yields, and mild reaction conditions.

A new method for C(sp2)-H sulfonylmethylation with glyoxylic acid and sodium sulfinates

We herein describe a C4 sulfonylmethylation of pyrazol-5-amines with glyoxylic acid and sodium sulfinates. The reaction only needed to add water as the solvent, and it featured mild reaction condition,...

Recent advances in the synthesis and applications of β-keto sulfones: new prospects for the synthesis of β-keto thiosulfones

This review mainly focuses on recent developments in the preparation of β-keto sulfones and their extensive synthetic applications. New prospects for the synthesis of β-keto thiosulfones have also been highlighted. Over the last decade, there has been exponential growth in the direct construction of β-keto sulfones using a wide variety of keto and sulfonyl precursors. Of note, the most promising photoredox transformations and electrochemical synthesis methods of β-keto sulfones are also presented. Moreover, β-keto sulfones are versatile building blocks in organic synthesis due to their three essential functional groups: sulfonyl, carbonyl, and active methylene moieties. The convenient preparation of β-keto sulfones allows the synthesis of many valuable carbocyclic and heterocyclic compounds, and the effortless removal of the sulfonyl moiety via transformations is supported. The chemistry of β-keto sulfones (2013 to present) can be divided into several sections based on the sulfonyl surrogates, and ubiquitous synthetic strategies were systematically outlined.

Oxidative Sulfonylation of Hydrazones Enabled by Synergistic Copper/Silver Catalysis

A copper/silver-cocatalyzed protocol for oxidative sulfonylation of hydrazones is demonstrated. A wide range of β-ketosulfones and N-acylsulfonamides are directly synthesized in moderate to good yields. Our work provides a viable method for scalable preparation of β-ketosulfone derivatives that have found wide applications in the pharmaceutical industry.

Synthesis and applications of sodium sulfinates (RSO2Na): a powerful building block for the synthesis of organosulfur compounds

This review highlights the preparation of sodium sulfinates (RSO2Na) and their multifaceted synthetic applications. Substantial progress has been made over the last decade in the utilization of sodium sulfinates emerging as sulfonylating, sulfenylating or sulfinylating reagents, depending on reaction conditions. Sodium sulfinates act as versatile building blocks for preparing many valuable organosulfur compounds through S-S, N-S, and C-S bond-forming reactions. Remarkable advancement has been made in synthesizing thiosulfonates, sulfonamides, sulfides, and sulfones, including vinyl sulfones, allyl sulfones, and β-keto sulfones. The significant achievement of developing sulfonyl radical-triggered ring-closing sulfonylation and multicomponent reactions is also thoroughly discussed. Of note, the most promising site-selective C-H sulfonylation, photoredox catalytic transformations and electrochemical synthesis of sodium sulfinates are also demonstrated. Holistically, this review provides a unique and comprehensive overview of sodium sulfinates, which summarizes 355 core references up to March 2020. The chemistry of sodium sulfinate salts is divided into several sections based on the classes of sulfur-containing compounds with some critical mechanistic insights that are also disclosed.

Silver-promoted oxidative sulfonylation and ring-expansion of vinylcyclopropanes with sodium sulfinates leading to dihydronaphthalene derivatives

Silver-promoted sulfonylation and ring-expansion of vinylcyclopropanes with sodium sulfinates is established for the construction of 1-sulfonylmethylated 3,4-dihydronaphthalenes. This sulfonylation process involves a radical pathway, including sulfonyl radical formation, radical addition, ring-opening and cyclization. The 1-sulfonylmethylated 3,4-dihydronaphthalenes can be converted into other useful products.

Sulfated tungstate/dioxygen: a new catalytic system for oxysulfonylation of styrenes to form β-keto sulfones

A new green cat./O₂ oxidation system is mild, safe, heterogeneous, simple to make, stable, noncorrosive, produces N₂ as by product, and has an easy to recover–reuse catalyst and wide substrate scope.

A one-pot protocol for the synthesis of β-ketosulfones from α,α-dibromoketones

A one-pot debromination/sulfonylation strategy was developed for the direct transformation of α,α-dibromoketones into β-ketosulfones in the presence of sulfinate salts in a methanol solution.