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Cysteine plays a crucial role in the development of an efficient copper-catalyst system, where its thiol group serves as a strong anchoring site for metal coordination. By immobilizing copper onto cysteine-modified, polydopamine-coated magnetite particles, this advanced catalytic platform exhibits exceptional stability and catalytic activity. Chemical modification of the polydopamine (PDA) surface with cysteine enhances copper salt immobilization, leading to the formation of the Fe3O4@PDA-Cys@Cu platform. This system was evaluated in palladium-free, copper-catalyzed Sonogashira coupling reactions, effectively catalyzing the coupling of terminal acetylenes with aryl halides. Additionally, the Fe3O4@PDA-Cys@Cu platform was employed in click reactions, confirming the enhanced catalytic efficiency due to increased copper content. The reusability of the platform was further investigated, demonstrating improved performance, especially in recyclability tests in click reaction, making it a promising candidate for sustainable heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

A versatile catalytic platform consisting of pyridine‐containing oxalamide and copper salt was developed. The resulting complexes were fully characterized by spectroscopic analyses, showing a successful complexation of copper metal. The applicability of the newly prepared platforms was evaluated in a one‐pot three‐components system for the preparation of 1,4‐disubstituted 1,2,3‐triazole via 1,3‐dipolar cycloaddition of terminal acetylenes, benzyl surrogates, and sodium azide in an aqueous environment. The corresponding cyclization proceeded smoothly affording the expected triazole products in moderate to good yields. In addition, the transformation of arylboronic acids to the corresponding phenols via ipso‐hydroxylation was also explored using the same platform in an aqueous basic condition. In the course of the study, unfortunately, some drawbacks that could limit the applicability of the catalytic platform were also observed especially in terms of recyclability of the platforms. [ABSTRACT FROM AUTHOR]

A novel catalyst has been afforded by immobilizing Cu(OAc)2 salt to polydopamine‐coated magnetite (Fe3O4). The catalytic platform (Fe3O4@PDA@Cu) was fully characterized by Fourier transform infrared, Energy‐dispersive X‐ray, Scanning Electron Microscopy, and Thermogravimetric Analysis. The catalytic activity of the Fe3O4@PDA@Cu nanocatalyst was investigated in a green and effective synthesis of click reaction by applying three‐component reactions of azide, alkyne, and benzyl surrogates in water, providing the corresponding 1,2,3‐triazoles in high yield. Furthermore, the present nanocatalyst could be easily separated by an external magnet and reused several times without considerable reduction of its catalytic efficiency. Operational simplicity, environmental friendliness, economical processing, and easy workup are the features of the present protocol. [ABSTRACT FROM AUTHOR]

The simple combination of readily available, recoverable, and recyclable magnetite (Fe3 O4) nanoparticles and an environmentally friendly oxidant (H2 O2) induced the effective functional group transformation of arylboronic acids into their corresponding phenols under mild conditions. Moreover, subsequent treatment of the reaction intermediate with appropriate electrophiles was accomplished in a one-pot system, leading to the formation of halophenols and phenolic derivatives. [ABSTRACT FROM AUTHOR]

Research elucidates a facile synthetic protocol for preparing benzylic manganese reagents starting with benzylic halide. The functionalized and nonfunctionalized benzylic manganese halides is prepared from benzyl alcohols via benzyl sulfonates and phosphates. Data suggest that the synthetic strategy can be applied for obtaining resorcinolic lipid derivatives as well.

The use of highly reactive manganese in the reductive dimerization of aryl aldehydes to produce the corresponding coupling products, namely vicinal diamines and 1,2-diols, in high yields was described. Except for aryl ketones, the diastereoselectivities measured were generally poor. The research further demonstrated that highly reactive manganese can also act as an excellent single-electron donor in organic synthesis.

The combination of a readily available palladium catalyst and an eco‐friendly basic aqueous solution of room‐temperature ionic liquid, choline hydroxide (ChOH), was used in a facile protocol alternative to the Sonogashira coupling reaction, alkynylation of aryl halides in the absence of a copper cocatalyst and an external base. The dual nature of ChOH to act as a base and a green solvent played a crucial role in the catalytic cycle. The coupling reaction progressed efficiently to form a CspCsp2 bond under the identified conditions although the reaction outcome depended significantly on the substrates. [ABSTRACT FROM AUTHOR]

Benzylic lithium reagents are usually prepare through bond cleavage reactions or transmetalation reactions, but complex mixtures and homo-coupling products may form. An alternative synthetic method is reported, to directly form nonfunctionalized and functionalized benzylic manganese halides from reactive manganese and benzylic halides. The subsequent cross-coupling results in extremely good yields with several electrophiles.