Cyclopalladated ferrocenylimines: efficient catalysts for homocoupling and Sonogashira reaction of terminal alkynes

Imine Palladacycles: Synthesis, Structural Analysis and Application in Suzuki–Miyaura Cross Coupling in Semi-Aqueous Media

Treatment of the imines a–c with palladium(II) acetate in acetic acid yielded the μ-acetate dinuclear complexes 1a–c, which readily reacted with sodium chloride or bromide to provide μ-halide analogues. The reaction of the latter with nitrogen, phosphorus and oxygen donor nucleophiles yielded new imine palladacycles following the cleavage of the Pd₂X₂ unit. The complexes were fully characterized by microanalysis, ¹H, ¹³C and ³¹P NMR spectroscopies, as appropriate. The compounds were applied as catalysts in the Suzuki–Miyaura coupling reaction in aqueous and semi-aqueous media.

Homocoupling of terminal alkynes catalyzed by CuCl under solvent-free conditions

A series of symmetrical 1,4-disubstituted buta-1,3-diynes is prepared with excellent yields (up to 95%) through homocoupling of terminal alkynes catalyzed by a copper salt under solvent-free conditions. This method provides an environmentally friendly process to prepare 1,3-diynes in short reaction times under mild conditions. Furthermore, the method is suitable for a wide substrate scope and has excellent functional group compatibility. The reaction can also be scaled up to gram level.

Palladium iminophosphorane complexes: the pre-cursors to the missing link in triphenylphosphane chalcogenide metallacycles

A dinuclear iminophosphorane palladacycle produces the missing link in the triphenylphosphane chalcogenide series of metallacycles.

The Homocoupling Reaction of Aromatic Terminal Alkynes by a Highly Active Palladium(II)/AgNO₃ Cocatalyst in Aqueous Media Under Aerobic Conditions

A new and efficient Pd(II)/AgNO₃-cocatalyzed homocoupling of aromatic terminal alkynes is described. Various symmetrical 1,4-disubstituted-1,3-diynes are obtained in good to excellent yields. This protocol employs a loading with relatively low palladium(II) in aqueous media under aerobic conditions.

An efficient mesoporous carbon nitride (g-C3N4) functionalized Pd catalyst for carbon–carbon bond formation reactions

Pd-nanoparticles on mesoporous nitrogen-rich carbon nitride (MCN) serves as an efficient heterogeneous catalyst for Sonogashira cross-coupling reactions.

Efficient and environmentally friendly Glaser coupling of terminal alkynes catalyzed by multinuclear copper complexes under base-free conditions

An efficient catalytic system with multinuclear copper complexes as catalysts has been developed for the aerobic Glaser coupling reaction, which adopts environmentally friendly water as the solvent at room temperature under base-free condition.

Palladium precatalysts containing meta-terarylphosphine ligands for expedient copper-free Sonogashira cross-coupling reactions

Novel precatalysts containing meta-terarylphosphine ligands have set a new standard for high performance and practicality in copper-free Sonogashira cross-coupling catalysis using simple and reliable protocols.

A Green Approach for Copper-Free Sonogashira Reaction of Aryl Halides with Phenylacetylene in the Presence of Nano-Pd/Phosphorylated Silica (SDPP/Pd0)

Silicadiphenyl phosphinite (SDPP) is used as the solid support for the generation of nano SDPP/Pd(0) from PdII as pre-catalyst. This nano catalyst was used for the efficient copper-free Sonogashira reaction of aryl halides in PEG-200 as a solvent. The nano Pd(0) that can be used as pre-prepared or as in situ-generated catalyst exhibited excellent reactivity and stability in the Sonogashira cross-coupling reactions with different aryl iodides, bromides, and also chlorides. This heterogeneous catalyst can be easily recovered and reused in several runs. The use of PEG as solvent and K2CO3 as inorganic base together with the heterogeneous nature of the reaction can be considered as green conditions for this reaction.

Copper immobilized on nano-silica triazine dendrimer (Cu(ii)-TD@nSiO2) catalyzed synthesis of symmetrical and unsymmetrical 1,3-diynes under aerobic conditions at ambient temperature

Highly efficient synthesis of symmetrical and unsymmetrical 1,3-diynes catalyzed by Cu(ii)-TD@nSiO₂/DBU is reported.

A facile copper(I)-catalyzed homocoupling of terminal alkynes to 1,3-diynes with diaziridinone under mild conditions

A novel and efficient Cu(I)-catalyzed oxidative homocoupling of terminal alkynes with diaziridinone as an oxidant is described. Various terminal alkynes can be transformed into the corresponding 1,3-diynes in good yields. The reaction process is base-free, operationally simple, and amenable to the gram scale.