Alkyl Aryl Sulfones Research Articles

Denitrogenation of tosylhydrazones: synthesis of aryl alkyl sulfones catalyzed by a phenalenyl-based molecule

An efficient method is developed for the photoinduced generation of a radical species based on the smallest odd alternant polyaromatic hydrocarbon phenalenyl, and its application in redox catalysis for denitrogenative sulfonylation of tosylhydrazones.

Alkyl (Het)Arylsulfones from SuFEx Reagents via Photochemical S-F Bond Activation.

A visible light-induced S-F bond activation of sulfur fluoride exchange (SuFEx) reagents to generate alkyl sulfones is described. The method is free of transition metals and relies on the use of commercially available commodity chemicals. In addition, this method demonstrates the first photoredox functionalization of SuFEx reagents. The reaction has a diverse substrate scope, with applications in various aryl sulfonyl fluorides, both activated and unactivated alkenes.

Nickel catalyzed three-component sulfonylation of non-activated alkyl chlorides.

We describe a nickel-catalyzed three-component sulfonylation of readily available non-activated alkyl chlorides. A wide range of alkyl aryl sulfones can be synthesized from alkyl chlorides, aryl boronic acids, and potassium metabisulfite, a cheap, efficient, and commercially available SO2 source under simple and easy-to-handle reaction conditions. High selectivity can be achieved with a slight excess of phenylboronic acid and a sulfur dioxide source.

Cu-mediated vs. Cu-free selective borylation of aryl alkyl sulfones.

A Cu-catalysed borylation of aryl alkyl sulfones was developed for the high yield synthesis of versatile arylboronic esters using a readily prepared NHC-Cu catalyst. In addition, the selective cleavage of either alkyl(C)-sulfonyl or aryl(C)-sulfonyl bonds of a cyclic sulfone via Cu-free or Cu-mediated processes generates the corresponding sulfinate salts, which can be further derivatised to provide sulfonyl-containing boronate esters, such as sulfones and sulfonyl fluorides.

Cobalt‐Catalyzed Redox‐Neutral Sulfonylative Coupling from (Hetero)aryl Boronic Acids, Ammonium Salts and Potassium Metabisulfite

AbstractAn efficient cobalt‐catalyzed redox‐neutral sulfonylative coupling to afford (hetero)aryl alkyl sulfones from boronic acids, ammonium salts and potassium metabisulfite has been realized. Commercially available and air‐stable CoCl2, in combination with phenanthroline ligand, is sufficient to achieve rapid and high‐yielding conversion of the reactants into the corresponding sulfones. This practical transformation proceeds smoothly through C−N bond cleavage under redox‐neutral catalytic conditions and shows broad functional‐group tolerance. Other carbon based electrophiles, including diaryliodonium salts, heteroaryl halides, and carbonates were compatible. Further transformation of aryl alkyl sulfones then allows conversion into olefins, alkenyl sulfones and halogenated sulfones, respectively, in a one‐pot process.

Visible-Light-Catalyzed in Situ Denitrogenative Sulfonylation of Sulfonylhydrazones.

A photocatalyzed in situ denitrogenative sulfonylation of N-arylsulfonyl hydrazones has been developed. This transformation provides a low-carbon strategy to assemble arylalkyl sulfones in a stepwise denitrogenation/sulfonylation manner.

One-pot synthesis of sulfones via Ni(II)-catalyzed sulfonylation of boronic acids, Na2S2O5 and benzylic ammonium salts

A one-pot nickel-catalyzed synthesis of (hetero)aryl alkyl sulfones from readily available boronic acids, sodium metabisulfite and benzylic ammonium salts as electrophiles is described. This general and efficient synthetic process is of broad scope, occurs in two steps, and delivers structural diverse sulfones, and the intermediate sulfinate is isolated. The transformation exhibits application of benzylic ammonium salts as novel electrophiles for direct insertion of SO2 as a novel area to be investigated.

General sulfone construction via sulfur dioxide surrogate control

A highly efficient one-step synthesis of alkyl–alkyl and aryl–alkyl sulfones with tuneable masked “SO2” sources is described.

Lewis Base Promoted, Direct 1,4-Conjugate Addition to Quinone Imine Ketals: Efficient Access to Unsymmetrical Diaryl Sulfones

An alternative approach with eco-friendliness and high efficiency for the preparation of unsymmetrical diaryl sulfones has been developed. The strategy takes advantage of the reaction of sulfonyl hydrazides with quinone imine ketals catalyzed by DABCO (triethylenediamine) in ethanol. This transformation proceeds via a Lewis base promoted, direct 1,4-conjugate addition/sulfonylation/alcohol elimination reaction sequence. The protocol provides an efficient approach to access an array of diverse unsymmetrical diaryl and heterodiaryl sulfones, aryl alkyl sulfones and aryl vinyl sulfones in good to excellent yields.

The recycling of sulfur dioxide

Sulfur-containing compounds are commonly found in important fossil fuels, such as coal and petroleum etc. Therefore, in the process of utilizing these energy sources, we will inevitably produce a large amount of sulfur dioxide gas. According to statistics, the annual emission of sulphur dioxide is 1.5 billion tons worldwide. Sulfur dioxide is one of the four core pollutants in air (nitrogen dioxide, ozone and solid particles are other three core pollutants), its content in the air directly affects the ecological environment and human healt. Meanwhile, sulfur dioxide is widely used as food additives, bleaching agents and other chemical raw materials, and this usage accounts is only 1.6% of its emissions. Sulfonyl-containing compounds exist widely in the drug and organic photoelectric material molecules. How to convert harmful sulfur dioxide into useful chemical products has become a scientific problem demanding prompt solution. In 1957, Meerwein et al. developed the synthesis of arylsulfonyl chlorides from aryl diazonium salts and SO2 gas in the presence of a catalytic amount of CuCl. Afterwards, some CuCl-catalyzed strategies were developed and applied to preparations of aryl sulfonyl chlorides from different organometallic reagent and SO2 gas. Sulfur dioxide, as a toxic gas, is not easy to handle and store in the process of its use. Therefore, the development of sulfur dioxide gas surrogates has become an important research direction in organic chemistry. In 2010, the Willis group employed the known complex DABSO DABCO·(SO2)2 (DABCO=1,4-diazabicyclo [2.2.2] octane) to synthesize aryl N -aminosulfonamides via the palladium- catalyzed three-component coupling of aryl iodides, hydrazines and DABSO. Subsequently, the Wu group described a palladium-catalyzed three-component coupling of arylboronic acids, DABSO and hydrazines in the presence of dioxygen. Inorganic sulfites also can be used as the source of sulfur dioxide. In 2012, the Wus group disclosed a palladium-catalyzed coupling of aryl halides, potassium metabisulfite (K2S2O5), and hydrazines for the synthesis of aryl N -aminosulfonamides. The Toste group developed a gold(I)-catalyzed sulfination of aryl boronic acids via the three-component coupling of aryl boronic acids, potassium metabisulfite and alkyl bromides. Shavnya et al. explored the palladium-catalyzed one-step synthesis of (hetero)aryl-alkyl sulfones via the three-component coupling of (hetero)arylboronic acids, potassium metabisulfite, and unactivated or activated alkylhalides. In 2017, our group reported a straightforward sulfur dioxide-iodine exchange protocol for the construction of diarylannulated sulfone employing the readily available inorganic sodium metabisulfite as a safe and convenient sulfur dioxide surrogate. Some structural novel π-conjugated molecules, which give great potentials as organic light emitting diodes (OLEDs) materials molecules, were successfully established through our strategy, Despite the great attention of direct introduction of sulfur dioxide into organic frameworks have been paid, there is still necessary to develop more stable, green, cheap and easy to handle sulfur dioxide surrogates.

Nickel‐Catalyzed Sulfonylation of C(sp2)–H Bonds with Sodium Sulfinates

AbstractThe first nickel‐catalyzed ortho‐sulfonylation of C(sp2)–H bonds with sodium sulfinates directed by (pyridin‐2‐yl)isopropylamine (PIP‐amine) is described. This strategy exhibits a broad substrate scope and good functional group tolerance with high monosulfonylation selectivity. Besides arenes and heteroarenes, the reaction can also be extended to alkenes, providing diverse diaryl and alkyl aryl sulfones in high yields. Furthermore, a plausible Ni(I)/Ni(III) mechanism is outlined based on our experimental results and related precedents.magnified image

Unexpected decarboxamidation of α-arylsulfonyl Weinreb amides by Grignard reagents: Synthesis of α-disubstituted arylsulfones

An unexpected decarboxamidation of α-arylsulfonyl Weinreb amides as a side reaction under the standard acylating conditions was found in Weinreb amides chemistry. The control experiments for mechanism study disclosed that α-sulfo group was necessary, and α-quaternary carbon was the key factor for the reaction. Meanwhile, an efficient method was established for the preparation of secondary alkyl arylsulfones by this unexpected C―C bond cleavage reaction using excess Grignard reagent.

Synthesis of Alkyl Aryl Sulfones via Reaction of N-Arylsulfonyl Hydroxyamines with Electron-Deficient Alkenes.

Alkyl aryl sulfones were prepared in high yields via the reaction of N-arylsulfonyl hydroxylamines with electron-deficient alkenes. These reactions have the advantages of simplicity, easily available starting materials and mild reaction conditions.

Direct Olefination of Alcohols with Sulfones by Using Heterogeneous Platinum Catalysts.

Carbon-supported Pt nanoparticles (Pt/C) were found to be effective heterogeneous catalysts for the direct Julia olefination of alcohols in the presence of sulfones and KOtBu under oxidant-free conditions. Primary alcohols, including aryl, aliphatic, allyl, and heterocyclic alcohols, underwent olefination with dimethyl sulfone and aryl alkyl sulfones to give terminal and internal olefins, respectively. Secondary alcohols underwent methylenation with dimethyl sulfone. Under 2.5 bar H2, the same reaction system was effective for the transformation of alcohol OH groups to alkyl groups. Structural and mechanistic studies of the terminal olefination system suggested that Pt(0) sites on the Pt metal particles are responsible for the rate-limiting dehydrogenation of alcohols and that KOtBu may deprotonate the sulfone reagent. The Pt/C catalyst was reusable after the olefination, and this method showed a higher turnover number (TON) and a wider substrate scope than previously reported methods, which demonstrates the high catalytic efficiency of the present method.

ChemInform Abstract: Palladium‐Catalyzed Synthesis of (Hetero)Aryl Alkyl Sulfones from (Hetero)Aryl Boronic Acids, Unactivated Alkyl Halides, and Potassium Metabisulfite.

AbstractA direct synthesis of aryl alkyl sulfones is achieved by Pd‐catalyzed reaction of arylboronic acids, alkyl halides, and potassium metabisulfite as source of the SO2‐unit.

Palladium-Catalyzed Synthesis of (Hetero)Aryl Alkyl Sulfones from (Hetero)Aryl Boronic Acids, Unactivated Alkyl Halides, and Potassium Metabisulfite.

A palladium-catalyzed one-step synthesis of (hetero)aryl alkyl sulfones from (hetero)arylboronic acids, potassium metabisulfite, and unactivated or activated alkylhalides is described. This transformation is of broad scope, occurs under mild conditions, and employs readily available reactants. A stoichiometric experiment has led to the isolation of a catalytically active dimeric palladium sulfinate complex, which was characterized by X-ray diffraction analysis.

Palladium‐Catalyzed Synthesis of (Hetero)Aryl Alkyl Sulfones from (Hetero)Aryl Boronic Acids, Unactivated Alkyl Halides, and Potassium Metabisulfite

AbstractA palladium‐catalyzed one‐step synthesis of (hetero)aryl alkyl sulfones from (hetero)arylboronic acids, potassium metabisulfite, and unactivated or activated alkylhalides is described. This transformation is of broad scope, occurs under mild conditions, and employs readily available reactants. A stoichiometric experiment has led to the isolation of a catalytically active dimeric palladium sulfinate complex, which was characterized by X‐ray diffraction analysis.

Pd(II)-Catalyzed Direct Sulfonylation of Unactivated C(sp(3))-H Bonds with Sodium Sulfinates.

A Pd(II)-catalyzed sulfonylation of unactivated C(sp(3))-H bonds with sodium arylsulfinates using an 8-aminoquinoline auxiliary is described. This reaction demonstrates excellent functional group tolerance with respect to both the caboxamide starting material and the sodium arylsulfinate coupling partner, affording a broad range of aryl alkyl sulfones. Moreover, the late-stage modification of complex molecules was achieved via this sulfonylation protocol.

ChemInform Abstract: Metal‐Free, High Yielding Synthesis of Unsymmetrical Biaryl, Bi(heteroaryl), Aryl Vinyl, Aryl Alkyl Sulfones via Coupling of Aryne with Sulfinic Acid Salts.

Here, we report a metal-free, high yielding method for the synthesis of unsymmetrical biaryl sulfones via coupling of aryne with sulfinic acid salts. The optimized condition also works efficiently for bi(heteroaryl), aryl vinyl and aryl alkyl sulfones. The present method took comparatively shorter reaction times and has good functional group compatibility.

ChemInform Abstract: Divergent Reactivity of Alkyl Aryl Sulfones with Bases: Selective Functionalization of ortho‐Aryl and α‐Alkyl Units Enabled by a Unique Carbanion Transmetalation.

ChemInform Abstract: Divergent Reactivity of Alkyl Aryl Sulfones with Bases: Selective Functionalization of ortho‐Aryl and α‐Alkyl Units Enabled by a Unique Carbanion Transmetalation.