I2/PhI(OAc)2 Copromoted Amination Reaction: Synthesis of α-Dicarbonylsulfoximine Derivatives by Incorporating an Intact Dimethyl Sulfoxide

Iron(II)-Catalyzed Nitrene Transfer Reaction of Sulfoxides with N-Acyloxyamides

An iron(II)-catalyzed nitrene transfer reaction of sulfoxides with N-acyloxyamides has been developed, leading to the efficient construction of N-acyl sulfoximines with high functional-group compatibility. The current catalytic transformation was carried out under an air atmosphere at ambient temperature and could be scaled up to gram scale with a catalyst loading of 1 mol %. Application of the methodology was demonstrated by facile C-H acetoxylation and olefination using the N-acyl sulfoximine as the directing group.

Synthetic Access to Aromatic α-Haloketones

α-Haloketones play an essential role in the synthesis of complex N-, S-, O-heterocycles; of which some exhibit a remarkable biological activity. Research further illustrated that α-bromo-, α-chloro-, and α-iodoketones are key precursors for blockbuster pharmacological compounds. Over the past twenty years, substantial advances have been made in the synthesis of these industrially relevant building blocks. Efforts have focused on rendering the synthetic protocols greener, more effective and versatile. In this survey, we summarised and thoroughly evaluated the progress of the field, established in the past two decades, in terms of generality, efficacy and sustainability.

Modification of Pyrrolo[2,1-a]isoquinolines and Pyrrolo[1,2-a]quinolines with Ammonium Acetate and Dimethyl Sulfoxide via Methylthiomethylation

An efficient methylthiomethylation of pyrroloisoquinolines and pyrroloquinolines has been reached by the use of ammonium acetate and dimethyl sulfoxide. Methylthiomethylated heterocycles can be obtained in moderate to good yields in most cases, while trace amounts to good yields of methylene-bridged products can be observed. Choice of DMSO activator and its amount have a great influence on the chemoselectivity of this process. It is worth noting that this process can also be scalable. Another feature of this process is that the product can be transformed to sulfone and sulfoxide easily.

Recent Advance on Dimethyl Sulfoxide (DMSO) Used as a Multipurpose Reactant

Abstract:

Dimethyl sulfoxide (DMSO) is not only a common and cheap aprotic polar solvent with low toxicity, but also serves as an efficient and multipurpose reactant and has widely been used in organic synthesis. DMSO as an important precursor can effectively introducea broad range of functional fragments into organic molecules, such as -Me, -CH, -CH2, -SMe2, -CH2SMe, -CH2SOMe, -SMe, -SO2Me, -SOMe or as O substituents, and serves as a mild oxidant in organic transformations. Many significant achievements based on DMSO as a synthon in synthetic chemistry have rapidly made over the past several years. To help researchers further understand the recent advances in the field, the review summarizes the applications of DMSO as carbon, sulfur, and oxygen sources and is used as the dual synthon in synthetic transformations.

A photocatalytic radical relay reaction of 2-methylthiolated phenylalkynones and potassium metabisulfite

The generation of methylsufonyl-containing thioflavones through a radical relay reaction of methylthiolated phenylalkynones and potassium metabisulfite in the presence of sodium methylsulfinate under visible light irradiation is developed.

Ten Years of Glory in the α-Functionalizations of Acetophenones: Progress Through Kornblum Oxidation and C-H Functionalization

This review article focuses on the α-functionalization of acetophenones involving Kornblum oxidation and C-H functionalizations. Although various other strategies, such as classical approaches, enamine approaches and umpolung strategy are also known for this functionalization, here we discuss mainly the Kornblum oxidation approach and C-H functionalization strategy as they have advantages over the others. In Kornblum oxidation, the reaction uses iodine and dimethylsulfoxide and proceeds through the formation of arylglyoxal as the key intermediate. In C-H functionalization, the reaction requires metal, or metal-free catalyst, and generates radical intermediate in most cases. α-Functionalization of acetophenones is very important because of their huge applications in the synthesis of various natural products and pharmaceuticals and, therefore, a number of research articles have been published in this area. However, no review articles are available so far. In this article, we present a succinct discussion of various important and novel reactions, along with their mechanisms, published since 2012 to date. We believe that this first review article in this field will give readers one-stop information on this topic and encourage further intriguing work in this area.

Iodine-Promoted Formal [3+2] Cycloaddition of Enaminone: Access to 2-Hydroxy-1,2-dihydro-pyrrol-3-ones with Quaternary Carbon Center

A novel iodine promoted cyclization of enaminone with aryl methyl ketones has been developed as a straightforward method for constructing 2-hydroxy-pyrrol-3(2H)-ones. This strategy affords structurally diverse 2-hydroxy-pyrrol-3(2H)-ones rings in high yields. Moreover, a quarternary alcohol has been constructed efficiently in the reaction. Product purification required only washing with CH₂Cl₂ solvent, thereby avoiding traditional chromatography and recrystallization, making this an example of group-assisted purification chemistry.

Employing Arylacetylene as a Diene Precursor and Dienophile: Synthesis of Quinoline via the Povarov Reaction

A novel I₂-mediated Povarov reaction of arylacetylenes and anilines for the synthesis of 2,4-substituted quinolines has been developed, in which arylacetylene first acts as both a diene precursor and dienophile. This work further develops the Povarov reaction to expand the types of diene precursors. Preliminary mechanistic studies indicate that the I₂/DMSO system realized the oxidative carbonylation of C(sp)-H of arylacetylene and then undergoes a [4 + 2] cycloaddition reaction.

Direct oxidation of N-ynylsulfonamides into N-sulfonyloxoacetamides with DMSO as a nucleophilic oxidant

N-Arylethynylsulfonamides are oxidized into N-sulfonyl-2-aryloxoacetamides directly and efficiently with dimethyl sulfoxide (DMSO) as both an oxidant and solvent with microwave assistance. DFT calculations indicate that DMSO nucleophilically attacks the ethylic triple bond and transfers its oxygen atom to the triple bond to form zwitterionic anionic N-sulfonyliminiums to trigger the reaction. Then it nucleophilically attacks the generated iminium intermediates to accomplish the oxidation via the second oxygen atom transfer. The current method provides a straightforward and efficient strategy to transform various N-arylethynylsulfonamides into N-sulfonyl-2-aryloxoacetamides, sulfonyl oxoacetimides, without any other electrophilic activators or oxidants.

Microwave-assisted direct oxidation of N-arylethynylsulfonamides with DMSO as a nucleophilic oxidant and solvent affords N-sulfonyl-2-aryloxoacetamides without any other additional electrophilic activators or oxidants.

Substrate-induced DMSO activation and subsequent reaction for rapid construction of substituted pyrimidines

A metal-free direct synthesis of pyrimidines from amidine hydrochlorides, ketones and DMSO through substrate-induced DMSO activation and involved reactions has been developed.

Synthesis of NH-Sulfoximines by Using Recyclable Hypervalent Iodine(III) Reagents under Aqueous Micellar Conditions

The synthesis of NH-sulfoximines from sulfides has been first developed under mild conditions in an aqueous solution with surfactant TPGS-750-M as the catalyst at room temperature. In this newly developed process, a simple and convenient recycling strategy to regenerate the indispensable hypervalent iodine(III) is used. The resulting 1,2,3-trifluoro-5-iodobezene can be recovered almost quantitively from the mixture by liquid-liquid extraction and then oxidized to give the corresponding iodine(III) species. This optimized procedure is compatible with a broad range of functional groups and can be easily performed on a gram scale, providing a green protocol for the synthesis of sulfoximines.

Methanesulfinylation of Benzyl Halides with Dimethyl Sulfoxide

A phenyltrimethylammonium tribromide-mediated nucleophilic substitution/oxygen transformation reaction of benzyl halides with DMSO has been developed. In this transition-metal-free reaction, DMSO acts as not only a solvent but also a "S(O)Me" source, thus providing a convenient method for the efficient and direct synthesis of various benzyl methyl sulfoxides.