Imidazopyridine Family: Versatile and Promising Heterocyclic Skeletons for Different Applications

In recent years, there has been increasing attention focused on various products belonging to the imidazopyridine family; this class of heterocyclic compounds shows unique chemical structure, versatile optical properties, and diverse biological attributes. The broad family of imidazopyridines encompasses different heterocycles, each with its own specific properties and distinct characteristics, making all of them promising for various application fields. In general, this useful category of aromatic heterocycles holds significant promise across various research domains, spanning from material science to pharmaceuticals. The various cores belonging to the imidazopyridine family exhibit unique properties, such as serving as emitters in imaging, ligands for transition metals, showing reversible electrochemical properties, and demonstrating biological activity. Recently, numerous noteworthy advancements have emerged in different technological fields, including optoelectronic devices, sensors, energy conversion, medical applications, and shining emitters for imaging and microscopy. This review intends to provide a state-of-the-art overview of this framework from 1955 to the present day, unveiling different aspects of various applications. This extensive literature survey may guide chemists and researchers in the quest for novel imidazopyridine compounds with enhanced properties and efficiency in different uses.

"One-Pot" In Situ Tandem Reaction─Dy(III) Coordination-Catalyzed Multicomponent Condensation of Salicylaldehyde Derivatives to Obtain Ketals

It is difficult to subject simple reaction starting materials to a "one-pot" in situ tandem reaction without post-treatment under mild reaction conditions to obtain multimers with complex structural linkages. In organic synthesis, acetal reactions are often used to protect derivatives containing carbonyl functional groups. Therefore, acetal products tend to have very low stability, and performing multi-step condensation to obtain complex multimeric products is difficult. Herein, we achieved the first efficient multiple condensation of o-vanillin derivatives using Dy(OAc)₃·6H₂O undergoing a "one-pot" in situ tandem reaction under mild solvothermal conditions to obtain a series of dimers (I and II, clusters 1 and 2) and trimers (I and II, clusters 3 and 4). When methanol or ethanol is used as the solvent, the alcoholic solvent participates in acetal and dehydration reactions to obtain dimers (I and II). Surprisingly, when using acetonitrile as the reaction solvent, the o-vanillin derivatives undergo acetal and dehydration reactions to obtain trimers (I and II). In addition, clusters 1-4 all showed distinct single-molecule magnetic behaviors under zero-field conditions. To the best of our knowledge, this is the first time that multiple acetal reactions catalyzed by coordination-directed catalysis under "one-pot" conditions have been realized, opening a new horizon for the development of fast, facile, green, and efficient synthetic methods for complex compounds.

Facile synthesis of a nano titanium catalyst and its performance in selective oxidation of aromatic and pyridinic alcohols under visible light

The oxidation of alcohols to the corresponding carbonyl compounds is of great significance in chemical synthesis and fine chemical production.