Heterogeneous versus Homogeneous Palladium Catalysts for Cross‐Coupling Reactions

Abstract

A large number of immobilized-Pd-catalysts for cross-coupling reactions have been introduced in the last decade. Are the observed catalyzed reactions truly heterogeneous or are they homogeneous due to leached palladium? This account critically addresses the leaching issue by selectively referring to some of the newly developed catalytic systems in an attempt to evaluate said systems based on uniform criteria. The report is concluded by identifying the relevant chemical and structural challenges in the field

Chemical reaction engineering, process design and scale-up issues at the frontier of synthesis: Flow chemistry

“…Different configurations including a Pd-based precatalysts have been developed [58]. The issue of possible Pd leaching from heterogenised catalysts and its influence on various coupling reactions has been considered by Pagliaro et al [28]. Microfluidic extraction has been also coupled to cross-coupling [59].…”

Upgrading Lignocellulosic Biomasses: Hydrogenolysis of Platform Derived Molecules Promoted by Heterogeneous Pd-Fe Catalysts

“…Palladium has a lower cost and more abundant reserves than platinum (that is still the most widely used element in catalysis) [92,93]. Homogeneous and heterogeneous palladium-based catalysts have found a potential application in several industrial reactions including hydrogenation, dehydrogenation, hydrogenolysis, reforming, oxidation, coupling reactions, carbonylation/decarbonylation and hydrodesulphurization [94][95][96][97][98][99][100][101][102][103][104][105][106]. With respect to other PGM elements, palladium is characterized by a fundamental electronic configuration unique among transition metals (4d 10 , 5s 0 ) [107] that can be strongly influenced by the coordination environment [108].…”

A fluorescence active catalyst support comprising carbon quantum dots and magnesium oxide doping for stabilization of palladium nanoparticles: Application as a recoverable catalyst for Suzuki reaction in water

“…[8][9][10][11] Palladium catalyzed cross-coupling reactions are important approaches for the formation of carbon-carbon and carbon-heteroatom bonds [12][13][14][15][16][17][18]. In recent years, because of high toxicity and price of palladium, growing interest has been paid to development of different heterogeneous palladium catalysts [19][20][21][22]. Magnesium oxide and clay minerals with high surface area can be found widely in nature and have been used as catalysts or as supports for stabilization of transition metal catalysts [23][24][25][26][27].…”