Palladium Catalyst For Heck Reaction Research Articles

A Novel Reusable Polymer Supported Palladium Catalyst for HeckReaction

With the rapid development of “green” chemistry; researchers are highly interested towards more sustainable approaches and prefer to choose eco-friendly synthetic routes and materials. This paper deals with the development of a novel reusable heterogeneous palladium catalyst for Heck reaction. The catalyst (mPAN-Pd) was developed by a simple procedure via synthetic modification of polyacrylonitrile (PAN) with monoethanolamine (MEA) followed by complexation with palladium chloride (PdCl2). After detailed characteristic studies, the catalytic efficiency of mPAN-Pd in Heck coupling reaction was systematically evaluated and optimised the reaction condition through a set of experiments. This heterogeneous catalytic system was found be applicable over a series of aryl halides and terminal alkenes leading to corresponding coupling products in good yields. Furthermore, this catalyst offers easy recyclability by simple filtration and reused for at least 5 cycles of Heck reaction without losing much of its activity.

Poly(hydroxamic acid) palladium catalyst for heck reactions and its application in the synthesis of Ozagrel

Bio-waste corn-cob cellulose supported poly(hydroxamic acid) palladium complex was synthesized and it is characterized using some different techniques such as FTIR, FESEM, HRTEM, EDX, XPS, UV–vis, TGA and ICP-AES analyses. The cellulose supported heterogeneous palladium complex showed high stability and catalytic activity toward Mizoroki-Heck reaction of aryl/heteroaryl halides and arenediazonium tetrafluoroborate with a variety of olefins to give the corresponding coupling products in up to 97% yield. The palladium complex was also applied to the synthesis of Ozagrel a thromboxane A2-synthetase inhibitor with excellent yield. The complex was separated from the reaction mixture by simple filtration and repeatedly used up to seven times without significant loss of its catalytic performance.

A highly efficient and recyclable fluorous palladium catalyst for Heck reactions in water

A fluorous nano-palladium catalyst has been synthesized and characterized. The catalyst is highly active for the Heck reaction of aryl halides with substituted styrenes in water under air. The corresponding Heck products were obtained in high yields with good stereoselectivity (E/Z up to 98:2). In addition, the catalyst could be recovered by fluorous liquid–liquid separation and reused four times without significant loss of activity or stereoselectivity. The Heck reaction catalyzed by a new fluorous nano-palladium catalyst in water to afford the products in high yields has been described. The catalyst can be recovered by fluorous liquid–liquid separation and reused for several times without significant loss of activity.

Preparation and application of SBA-15-supported palladium catalyst for Heck reaction in supercritical carbon dioxide

A new method for the preparation of SBA-15-supported palladium catalyst for Heck reaction in supercritical carbon dioxide was presented. The newly formed SBA-15-supported palladium catalyst (Ph-SBA-15-PPh3-Pd) exhibited high catalytic activity for the Heck reaction of 4-nitrobromobenzene with methyl acrylate. The catalyst can be reused several times without a loss of activity.

A novel fluorous palladium catalyst for Heck reaction in a fluorous biphase system (FBS)

Palladium(II) perfluorooctanesulfonate [Pd(OSO 2R f8) 2] catalyses the highly efficient Heck reaction in the presence of a catalytic amount of a perfluoroalkylated-pyridine as a ligand in a fluorous biphase system (FBS) composed of toluene and perfluorodecalin. The fluorous phase containing the active palladium species is easily separated and can be reused several times without a significant loss of catalytic activity.

A Practical Recycle of a Ligand-Free Palladium Catalyst for Heck Reactions

Ligand-free palladium can be recovered almost quantitatively from Heck reaction mixtures by filtration after its deposition on a carrier such as silica or celite. Subsequently, it is re-activated to its original activity by adding a small amount of iodine or bromine prior to the next reaction cycle. The catalyst results in excellent yields and selectivities, even for the less reactive aryl bromides. A catalytic cycle based on anionic palladium intermediates is proposed.

A New Efficient Palladium Catalyst for Heck Reactions of Deactivated Aryl Chlorides

A new palladium catalyst consisting of Pd(Dba)2 and di-1-adamantyl-n-butylphosphine is described for the Heck reaction of non-activated and deactivated aryl chlorides. The new catalyst is more efficient and gives improved results compared to the previously known best catalyst system.