Search

Earth abundant metal‐based heterogeneous catalysts with highly active and at the same time stable isolated metal sites constitute a key factor for the advancement of sustainable and cost‐effective chemical synthesis. In particular, the development of more practical, and durable iron‐based materials is of central interest for organic synthesis, especially for the preparation of chemical products related to life science applications. Here, we report the preparation of Fe‐single atom catalysts (Fe‐SACs) entrapped in N‐doped mesoporous carbon support with unprecedented potential in the preparation of different kinds of amines, which represent privileged class of organic compounds and find increasing application in daily life. The optimal Fe‐SACs allow for the reductive amination of a broad range of aldehydes and ketones with ammonia and amines to produce diverse primary, secondary, and tertiary amines including N‐methylated products as well as drugs, agrochemicals, and other biomolecules (amino acid esters and amides) utilizing green hydrogen. [ABSTRACT FROM AUTHOR]

Organic oxidation reactions (OORs) powered by renewable energy sources are gaining importance as a favorable alternative to oxygen evolution reaction, with the promise of reducing the cell potential and enhancing the overall viability of the water electrolysis. This comprehensive review delves into the electrochemical oxidation of diverse organic compounds, including alcohols, aldehydes, amines, and urea, as well as biomass‐derived renewable feedstocks such as hydroxymethylfurfural and glycerol. The key focus centers on the role of nickel (Ni)‐based catalysts for these OORs. The unique redox activity and chemical nature of Ni have been proven instrumental for the sustainable and cost‐effective oxidation of various organic molecules more efficiently and selectively. This review article discusses how strategic choices, such as the selection of foreign metals, intercalating species, vacancies, defects, and a secondary element (e.g. chalcogens and non‐metals), contribute to tuning the electrochemical performances of a Ni‐based (pre)catalyst for OORs. Moreover, this review provides insights into the active species in various reaction environments and further explores reaction mechanisms, to apparent phase changes of the catalyst with the most relevant examples. Finally, the review not only elucidates the limitations of the current approaches but also outlines potential avenues for future advancements in OOR. [ABSTRACT FROM AUTHOR]

Production of value-added chemicals from renewable feedstocks is an attractive platform to alleviate the shortage of petroleum resources and to minimize CO2 emissions. Among different renewable feedstocks, glycerol is an organic triol molecule that is produced from triglycerides of plant and animal sources. This alcohol is produced as the main by-product in a large quantity of about 10% (w/w) in biodiesel production. In addition to its applications in food industries, and medicinal and personal care products, the utilization of glycerol as a key raw material in organic synthesis has garnered significant attention. As an example, selected technologies for the conversion of glycerol into other essential chemicals such as acrylic acid, 1,2-propanediol, glycerol carbonate, epichlorohydrin, and solketal have been well developed. In recent years, glycerol has also been used as the key starting material for the synthesis of amines in laboratories. In general amines are important fine and bulk chemicals used as central precursors and intermediates for advanced chemicals and many life science molecules including pharmaceuticals and agrochemicals. In the last five years, some key advancements have been made using glycerol in carbon–nitrogen bond-forming processes to prepare different kinds of amine in the presence of suitable catalytic systems. Based on the advantages of glycerol including its derived molecules as feedstocks and the importance of amines, we believe it is worthwhile to write a review summarizing the recent reports on glycerol amination and related reactions. In this regard, this review article discusses the latest developments in catalytic amination reactions using glycerol and its tangible applications in modern organic synthesis. We believe that this review will be interesting and beneficial to scientists working in the areas of catalytic utilization of glycerol aminations and valorization of renewable feedstocks. [ABSTRACT FROM AUTHOR]

A protocol for efficient N-alkylation of benzamides with alcohols in the presence of cobalt-nanocatalysts is described. Key to the success of this general methodology is the use of highly dispersed cobalt nanoparticles supported on carbon, which are obtained from the pyrolysis of cobalt(II) acetate and o-phenylenediamine as a ligand at suitable temperatures. The catalytic material shows a broad substrate scope and good tolerance to functional groups. Apart from the synthesis of a variety of secondary amides (>45 products), the catalyst allows for the conversion of more challenging aliphatic alcohols and amides, including biobased and macromolecular amides. The practical applicability of the catalyst is underlined by the successful recycling and reusability. [ABSTRACT FROM AUTHOR]

Catalytic hydrogenation and oxidative dehydrogenation of N‐heterocycles to produce tetrahydroquinoline and quinoline derivatives are important reactions of particular importance in the agrochemical and pharmaceutical industries. Herein, we report earth‐abundant cobalt nanoparticles supported on hydroxyapatite (HAP) as an inexpensive and efficient catalyst for the hydrogenation and reverse oxidative dehydrogenation of N‐heterocycles. The optimal nanocatalyst exhibits excellent activity in both reactions for a wide range of substrates including (iso)quinolines, acridine, benzo[h]quinoline, quinoxaline and indole. Reactions proceed under relatively mild conditions without requiring any additives. [ABSTRACT FROM AUTHOR]

Boronic esters find increasing applications as key starting materials and central intermediates in organic synthesis. Their synthesis from highly abundant and renewable feedstocks continues to be interesting. Here, we report an efficient and one-pot method for the synthesis of aryl/heteroaryl boronic esters from phenols. In this approach, phenols are first activated by sulfuryl fluoride to form aryl fluorosulfonates, followed by a palladium-catalyzed deoxygenative borylation reaction with bis(pinacolato)diboron to provide a series of boronic esters. This methodology exhibits excellent functional group tolerance and is applicable for the synthesis of natural products and current drug molecules. In addition, this protocol is also amenable for the borylation of biomass derived phenols, including naturally occurring and bioactive compounds. Notably, a novel boronate-based NIR fluorescent probe HTCPB was synthesized using this procedure and successfully employed in fluorescence bioimaging of H2O2 in mouse mammary cancer cells. [ABSTRACT FROM AUTHOR]