67456-93-3

Upstream product

• 6781-98-2 2,6-dimethyl-1-chlorobenzene 
• 119873-74-4 (E)-2-(phenyl)ethylenyldimethylsilanol 
• 139719-92-9 2-{2,6-dimethylphenyl}-1,3,2-dioxaborolane 
• 2206-94-2 1-acetoxy-1-phenylethene 
• 100-42-5 styrene 
• 108-38-3 m-xylene 
• 2192-33-8 2,6-dimethylbenzenediazonium tetrafluoroborate 
• 180783-48-6 2,6-dimethyl-1-(phenylethynyl)benzene 
• 536-74-3 phenylacetylene 
• 608-28-6 2,6-dimethyliodobenzene 
• 98-85-1 1-Phenylethanol 
• 1342307-11-2 2,6-dimethylphenyl 1H-imidazole-1-sulfonate 
• 6783-05-7 trans-2-phenylvinylboronic acid 
• 576-22-7 2-Bromo-m-xylene 

Downstream Products

• 180783-60-2 (Z)-1,3-bis(bromomethyl)-2-(2-phenylethenyl)benzene 

Relevant academic research and scientific papers

Copper(0) nanoparticle catalyzed Z-Selective Transfer Semihydrogenation of Internal Alkynes

The use of copper(0) nanoparticles in the transfer semihydrogenation of alkynes has been investigated as a lead-free alternative to Lindlar catalysts. A stereo-selective methodology for the hydrogenation of internal alkynes to the corresponding (Z)-alkenes in high isolated yields (86% average) has been developed. This green and sustainable transfer hydrogenation protocol relies on non-noble copper nanoparticles for reduction of both electron-rich and electron-deficient, aliphatic-substituted and aromatic- substituted internal alkynes. Polyols, such as ethylene glycol and glycerol, have been proven to act as hydrogen sources, and excellent stereo- and chemoselectivity have been observed. Enabling technologies, such as microwave and ultrasound irradiation are shown to enhance heat and mass transfer, whether used alone or in combination, resulting in a decrease in reaction time from hours to minutes. (Figure presented.).

Dehydrative Cross-Coupling of 1-Phenylethanol Catalysed by Palladium Nanoparticles Formed in situ under Acidic Conditions

A dehydrative cross-coupling of 1-phenylethanol catalysed by sugar derived, in situ formed palladium(0) nanoparticles under acidic conditions is realised. The acidic conditions allow for use of alcohols as a feedstock in metal-mediated coupling reactions via their in situ dehydration and subsequent cross-coupling. Extensive analysis of the size and morphology of the palladium nanoparticles formed in situ showed that the zero-valent metal was surrounded by hydrophilic hydroxyl groups. EDX-TEM imaging studies using a prototype silicon drift detector provided insight into the problematic role of molecular oxygen in the system. This increased understanding of the catalyst deactivation allowed for the development of the cross-coupling methodology. A 250-12,000 fold increase in molar efficiency was observed when compared to related two-step protocols that use alternative feedstocks for the palladium-mediated synthesis of stilbenes. This work opens up a new research area in which the active catalyst is formed, stabilised and regenerated by a renewable sugar.

In-situ-generated palladium nanoparticles in novel ionic liquid: an efficient catalytic system for Heck–Matsuda coupling

Abstract: A green, convenient, ecological and recyclable method comprising dual functionalized, task-specific, ionic liquid (IL)-triggered, in situ-generated Pd nanoparticles (NPs) and their catalytic application for Heck–Matsuda coupling of olefins is described. Both arenediazonium tetrafluoroborate and silica sulphate salts are coupled with olefins under ligand-free and aerobic conditions at ambient temperature furnishing excellent yields of products. The Ionic liquid used acts as a reducing as well as stabilizing agent for in situ-generated Pd NPs. The formed NPs were characterized by transmission electron microscopy (TEM) analysis, having a size below 50?nm, and exhibited high catalytic activity. The catalytic system can be reused for eight times effectively without any significant loss of activity. The method was found to be highly stereo-specific, giving exclusively the ‘E’ isomer.

Cyclodextrin-Grafted Silica-Supported Pd Nanoparticles: An Efficient and Versatile Catalyst for Ligand-Free C-C Coupling and Hydrogenation

Silica is an extremely versatile support, which is capable of hosting metal nanoparticles (NPs) and enhancing their stability and reactivity. In this study, a novel cyclodextrin/silica support for Pd NPs, which we have denoted Pd/Si-CD, has been prepared. The highly efficient and homogeneous impregnation of small palladium nanoparticles on this support has been carried out under conventional conditions, and ultrasound irradiation has been shown to have a beneficial effect on catalyst preparation. The catalyst exhibited excellent activity in ligand-free C-C Suzuki and Heck couplings with a large number of aryl iodide and bromides, in which microwave irradiation use cuts down reaction time. Pd/Si-CD have shown high activity and selectivity in the hydrogenation reaction, and the semihydrogenation of phenyl acetylene was also studied with excellent results.

Controlling olefin isomerization in the heck reaction with neopentyl phosphine ligands

The use of neopentyl phosphine ligands was examined in the coupling of aryl bromides with alkenes. Di-tert-butylneopentylphosphine (DTBNpP) was found to promote Heck couplings with aryl bromides at ambient temperature. In the Heck coupling of cyclic alkenes, the degree of alkene isomerization was found to be controlled by the choice of ligand with DTBNpP promoting isomerization to a much greater extent than trineopentylphosphine (TNpP). Under optimal conditions, DTBNpP provides high selectivity for 2-aryl-2,3-dihydrofuran in the arylation of 2,3-dihydrofuran, whereas TNpP provided high selectivity for the isomeric 2-aryl-2,5-dihydrofuran. A similar complementary product selectivity is seen in the Heck coupling of cyclopentene. Heck coupling of 2-bromophenols or 2-bromoanilides with 2,3-dihydrofurans affords 2,5-epoxybenzoxepin and 2,5-epoxybenzazepins, respectively.

Investigation of sol-gel supported palladium catalysts for Heck coupling reactions in o/w-microemulsions

Sol-gel supported palladium catalysts are investigated for the Heck coupling reaction between styrene and iodo-/bromobenzene to trans-stilbenes in o/w-microemulsions as alternative reaction medium. High conversions and selectivities are obtained with these catalysts and they show better catalytic performance than their commercial analogs Pd@SiO2 or Pd/C. The influence of the catalyst structure on the activity is investigated in detail showing mass transport limitations that can be optimized by the palladium loading. The catalyst is recyclable >6 times with negligible palladium leaching into the solution. Because of the good recyclability under retention of activity and selectivity, the influence of transport limitations is suppressed and the total catalyst efficiency is increased to more than 2.

PALLADIUM CATALYST, METHOD FOR ITS PREPARATION AND ITS USE

The invention relates to palladium(0)-tris{tri-[3,5-bis(trifluoromethyl)-phenyl]-phosphine} complex of formula (I), as well as to its preparation and use. This compound is outstandingly stable, and can be used as catalyst with excellent results.

Palladium-nanoparticle-catalyzed Matsuda-Heck reaction in water

An eco-friendly, simple method for Matsuda-Heck arylation of olefins catalyzed by in situ formed Pd nanoparticles is described in water operable at ambient temperature. A variety of arenediazonium salts were coupled with olefins under ligand-free and aerobic conditions in high yields and stereoselectivity.

A NEW PALLADIUM CATALYST, METHOD FOR ITS PREPARATION AND ITS USE

The invention relates to palladium(0)-tetrakis{tri-[3,5-bis(trifluoromethyl)- phenylj-phosphine} complex of formula (I), as well as to its preparation and use. This compound is outstandingly stable, and can be used as catalyst with excellent results.

Straightforward synthesis of phenanthrenes from styrenes and arenes

Semi-one-pot synthesis of phenanthrenes from styrenes and arenes was developed through cross-dehydrogenative coupling. A sequence of Heck-type coupling and photo-cyclization were involved and a variety of functionalities were tolerated. This method provides an effective and practical protocol towards the synthesis of substituted phenanthrenes. The Royal Society of Chemistry 2012.