I2-Promoted Multicomponent Dicyclization and Ring-Opening Sequences: Direct Synthesis of Benzo[e][1,4]diazepin-3-ones via Dual C-O Bond Cleavage

Iodine-Catalyzed Annulation Reaction of Ortho-Formylarylketones with Indoles: A General Strategy for the Synthesis of Indolylbenzo[b]carbazoles

The iodine-catalyzed cascade reaction of ortho-formylarylketones with indoles for the synthesis of indolylbenzo[b]carbazoles is reported. The reaction is initiated in the presence of iodine by two successive nucleophilic additions of indoles with an aldehyde group of ortho-formylarylketones, and the ketone does not undergo a nucleophilic addition and only involves in the Friedel-Crafts-type cyclization. A variety of substrates are tested, and the efficiency of this reaction is demonstrated with gram-scale reactions.

Rhodium-Catalyzed C-H Annulation of Free Anilines with Vinylene Carbonate as a Bifunctional Synthon

Chemical transformation with vinylene carbonate as an emerging synthetic unit has recently attracted considerable attention. This report is a novel conversion pattern with vinylene carbonate, in which such a vibrant reagent unprecedentedly acts as a difunctional coupling partner to complete the C-H annulation of free anilines. From commercially available substrates, this protocol leads to the rapid construction of synthetically versatile 2-methylquinoline derivatives (43 examples) with excellent functionality tolerance.

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.

Reactions involving aryl methyl ketone and molecular iodine: a powerful tool in the one-pot synthesis of heterocycles

The preparation of heterocyclic compounds has attracted great attention in organic chemistry because of their extensive application in the field of bioactive molecules, materials science, and natural products.

Revisiting applications of molecular iodine in organic synthesis

Molecular iodine contributes significantly to organic transformations in synthetic organic chemistry. It works effectively due to its mild Lewis acidic character, ability as an oxidizing agent, good moisture stability, and easy availability.

Recent advances in multi-component reactions and their mechanistic insights: a triennium review

This review summarizes the recent developments in MCRs, incorporating different strategies along with their mechanistic aspects.

Recent Advances in Iodine-Promoted C-S/N-S Bonds Formation

Sulfur-containing scaffold, as a ubiquitous structural motif, has been frequently used in natural products, bioactive chemicals and pharmaceuticals, particularly C-S/N-S bonds are indispensable in many biological important compounds and pharmaceuticals. Development of mild and general methods for C-S/N-S bonds formation has great significance in modern research. Iodine and its derivatives have been recognized as inexpensive, environmentally benign and easy-handled catalysts or reagents to promote the construction of C-S/N-S bonds under mild reaction conditions, with good regioselectivities and broad substrate scope. Especially based on this, several new strategies, such as oxidation relay strategy, have been greatly developed and accelerated the advancement of this field. This review focuses on recent advances in iodine and its derivatives promoted hybridized C-S/N-S bonds formation. The features and mechanisms of corresponding reactions are summarized and the results of some cases are compared with those of previous reports. In addition, the future of this domain is discussed.

Sulfoxide Reduction/C(sp3)-S Metathesis Cascade in Ionic Liquid

A sulfoxide reduction/C-S bond metathesis cascade between sulfoxides and alkyl bromides has been developed to access high-value sulfides without the use of any catalysts or bases. In this cascade, classical Kornblum oxidation is employed to reduce sulfoxides with alkyl bromides in ionic liquid. This protocol features high functional tolerance, mild conditions, promising scalability, and sustainable solvents.

Humic acid as an efficient and reusable catalyst for one pot three-component green synthesis of 5-substituted 1H-tetrazoles in water

Humic acid is a non toxic, inexpensive, easily available high-molecular weight polymer. A simple and facile one pot three-component synthesis of 5-substituted 1H-tetrazoles from aldehydes, hydroxyamine hydrochloride and sodium azide using humic acid as an efficient catalyst in water is described. The method reported has several advantages such as high to excellent yields, easy work-up, mild reaction conditions, use of water as a green solvent, and a commercially available, nontoxic and reusable catalyst.