Phosphine-free Sonogashira Coupling Reaction Research Articles

Palladium-free and phosphine-free Sonogashira coupling reaction of aryl halides with terminal alkynes catalyzed by boehmite nanoparticle-anchored Cu(I) diethylenetriamine complex

In this work, a novel diethylenetriamine-functionalized-boehmite nanoparticle-supported Cu(I) catalyst is synthesized. The catalyst prepared is then characterized by FT-IR spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction spectroscopy, and inductively coupled plasma techniques. The catalyst prepared shows great activity in the Sonogashira coupling reaction of aryl halides with terminal alkynes in DMF under an argon atmosphere. Moreover, it could be removed from the reaction mixture by means of simple filtration and used again for up to six runs without an appreciable loss in its activity.

A coordination driven self-assembled Pd6L8 nanoball catalyses copper and phosphine-free Sonogashira coupling reaction in both homogeneous and heterogeneous formats

A self-assembled Pd6L8 nanocage catalysed copper free Sonogashira reaction under mild and aerobic conditions, at 100 ppm catalyst loading in aqueous medium in the homogeneous phase, and at 500 ppm in the heterogeneous phase.

NiCl2·6H2O: an efficient catalyst precursor for phosphine-free Heck and Sonogashira cross-coupling reactions

An efficient and simple protocol for the Heck reaction of aryl iodides and bromides using NiCl2·6H2O as the pre-catalyst is presented. The reactions proceed well in ethylene glycol in the absence of phosphine ligands and reducing agent. Compared to the frequently used expensive palladium catalysts, the use of nickel catalyst has an economic advantage and hence, remains attractive for large or industrial scale preparations. The efficient copper- and phosphine-free Sonogashira coupling reaction of aryl iodides is also demonstrated using this catalytic system.

A heterogeneous and reusable nanopolymer-supported palladium catalyst for the copper- and phosphine-free Sonogashira coupling reaction under aerobic conditions in water

We report here the synthesis of a nanopolymer-supported palladium(II) complex catalyst, [PS-tet-Pd(II)] using a simple protocol. The catalyst was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), FT-IR, and energy dispersive X-ray spectroscopy (EDS). PS-tet-Pd(II) proves to be a useful heterogeneous catalyst in the copper- and phosphine-free Sonogashira coupling reaction in water. The catalyst can be recovered from the reaction mixture by simple filtration and reused several times without any significant loss of catalytic activity.

ChemInform Abstract: Sonogashira Coupling Reactions in Biodegradable Ionic Liquids Derived from Nicotinic Acid.

The biodegradable ionic liquids, 3-butoxycarbonyl-1-methylpyridinium bis(trifluoromethanesulfonyl)imides (1a–d), have been evaluated as solvents for copper- and phosphine-free Sonogashira coupling reactions. The stability of these ionic liquids toward basic conditions was analysed in order to further probe their utility for transition metal catalyzed reactions which require the presence of a base.

Copper- and phosphine-free Sonogashira coupling reactions of aryl iodides catalyzed by an N, N-bis(naphthylideneimino)diethylenetriamine-functionalized polystyrene resin supported Pd(II) complex under aerobic conditions

A polymer-supported palladium(II) N, N-bis(naphthylideneimino)diethylenetriamine complex is found to be a highly active catalyst for Sonogashira coupling reactions. The reactions are performed under copper- and phosphine-free conditions in an air atmosphere. The palladium catalyst is easily separated, and can be reused several times without significant loss in catalytic activity.

Synthesis and characterization of a polymer-anchored palladium(II) Schiff base complex and its catalytic efficiency in phosphine-free Sonogashira coupling reactions

A polymer-anchored Pd(II) Schiff base complex has been synthesized by reacting a polymeric amine with 2-pyridinecarboxaldehyde to get the polymer-anchored Schiff base, which was then reacted with palladium acetate. The catalyst was characterized by physicochemical and spectroscopic methods. It shows excellent catalytic activity in the Sonogashira coupling of phenylacetylene with aryl halides using triethylamine as a base and copper iodide as a co-catalyst in water under open air at 70 °C. We have also studied the effects of base and solvent on the coupling reaction. Sonogashira reactions of phenylacetylene with a variety of functionalized aryl halides were performed under the optimized reaction conditions. This catalyst gives excellent yields without the use of phosphine ligands. Further experiments showed that the catalyst can be used five times without much loss in the catalytic activity.

Sonogashira coupling reactions in biodegradable ionic liquids derived from nicotinic acid

The biodegradable ionic liquids, 3-butoxycarbonyl-1-methylpyridinium bis(trifluoromethanesulfonyl)imides (1a–d), have been evaluated as solvents for copper- and phosphine-free Sonogashira coupling reactions. The stability of these ionic liquids toward basic conditions was analysed in order to further probe their utility for transition metal catalyzed reactions which require the presence of a base.

An Amine-, Copper- and Phosphine-Free Sonogashira Coupling Reaction Catalyzed by Immobilization of Palladium in Organic–Inorganic Hybrid Materials

An immobilization of palladium in organic-inorganic hybrid materials-catalyzed Sonogashira coupling reaction has been described. Terminal alkynes reacted with aryl iodides and aryl bromides only in the presence of a 3-(2-aminoethylamino)-propyl-functionalized, silica gel-immobilized palladium catalyst under amine-, copper- and phosphine-free reaction conditions. The reaction generates the corresponding cross-coupling products in excellent yields. Furthermore, the silica-supported palladium can be recovered and recycled by a simple filtration of the reaction solution and used for 30 consecutive trials without any decreases in activity.