Photocatalyzed Facile Synthesis of α-Chloro Aryl Ketones with Polyaniline–g-C3N4–TiO2 Composite under Visible Light

Heterogeneous Photocatalytic Radical Synthesis of Aryl Allyl Sulfones

A photocatalytic synthesis of aryl allyl sulfones by a radical cascade reaction from an aryl diazonium salt, DABCO·(SO2)2 and 3-bromoprop-1-ene has been developed. This reaction employed ­DABCO·(SO2)2 as the SO2 source and a polyaniline–graphitic carbon ­nitride–titanium dioxide composite as the photocatalyst. A series of substrates were tolerated, providing the corresponding products in good yields. Moreover, the photocatalyst could be readily recovered and reused several times with only a slight decrease in its catalytic activity.

Electrochemical Difunctionalization of Terminal Alkynes: Access to 1,4-Dicarbonyl Compounds

1,4-Dicarbonyl compounds are versatile scaffolds for the heterocycle synthesis, including the Paal-Knorr reaction. Herein, a feasible electrosynthesis method to access 1,4-dicarbonyl compounds has been developed from simple alkynes and 1,3-dicarbonyl compounds. When the undivided cell is combined with the constant current mode, aryl alkynes containing numerous medicinal motifs with 1,3-dicarbonyl esters or ketones react smoothly. External oxidant and catalyst-free conditions conform to the requirements of green synthesis.

Generation of aryl radicals by redox processes. Recent progress in the arylation methodology

Arylation methods based on the generation and use of aryl radicals have been a rapidly growing field of research in recent years and currently represent a powerful strategy for carbon – carbon and carbon – heteroatom bond formation. The progress in this field is related to advances in the methods for generation of aryl radicals. The currently used aryl radical precursors include aryl halides, aryldiazonium and diaryliodonium salts, arylcarboxylic acids and their derivatives, arylboronic acids, arylhydrazines, organosulfur(II, VI) compounds and some other compounds. Aryl radicals are generated under mild conditions by single electron reduction or oxidation of precursors induced by conventional reagents, visible light or electric current. A crucial role in the development of the radical arylation methodology belongs to photoredox processes either catalyzed by transition metal complexes or organic dyes or proceeding without catalysts. Unlike the conventional transition metal-catalyzed arylation methods, radical arylation reactions proceed very often at room temperature and have high functional group tolerance. Without claiming to be exhaustive, this review covers the most important advances of the current decade in the generation and synthetic applications of (het)aryl radicals. Examples of reactions are given and mechanistic insights are highlighted.

The bibliography includes 341 references.

Application of metal oxide semiconductors in light-driven organic transformations

Herein, we provide an up-to-date overview of metal oxide semiconductors (MOS) as versatile and inexpensive photocatalysts to enable light-driven organic transformations.

Recent advances in modified TiO2 for photo-induced organic synthesis

The recent advancements of modified TiO₂ materials as photocatalysts for organic synthesis are summarized.

Cu2O/TiO2 nanoparticles as visible light photocatalysts concerning C(sp2)–P bond formation

A novel and efficient method has been developed for the construction of an aromatic-phosphorus (Ar-P) bond under visible light irradiation using Cu₂O/TiO₂ nanoparticles as inexpensive and available photocatalysts.