Ligand-free Stille cross-coupling reaction using Pd/CaCO3 as catalyst reservoir

Anchoring of Palladium onto Surface of Porous Metal–Organic Framework through Post-Synthesis Modification and Studies on Suzuki and Stille Coupling Reactions under Heterogeneous Condition

“…However, due to the leaching of palladium in the DMF medium reaction was performed in ethanol. Coelho et al reported ligand-free Pd/CaCO 3 for the Stille reaction and proposed a reaction mechanism, revealing that the leaching occurred to give rise to a very active “mononuclear Pd(0) species” that reacts faster with aryl halide, resulting in a homogeneous catalytic cycle . With an increasing concentration of water in the reaction medium, yield decreased gradually and no yield was obtained in presence of water only.…”

“…This is the major drawback of a heterogeneous catalytic system in comparison to their homogeneous counterpart. Coelho et al reported a ligand-free Pd/CaCO 3 system for the Stille reaction, where leaching occurred to give rise to a very active “mononuclear Pd(0) species” . Kim et al recently reported that the carbon nanotube supported Pd catalysts are efficient in the Stille coupling reaction with p -iodotoluene .…”

Efficient and Practical Cross‐Coupling of Arenediazonium Tetrafluoroborate Salts with Boronic Acids Catalyzed by Palladium(0)/Barium Carbonate

“…We were even able to work at only 1 mol% Pd, simply by using MeOH instead of i-PrOH (entry 14), while a lower loading (0.5 mol% Pd) was deleterious for this cross-coupling although still retaining a respectable yield (80%, entry 15). It is worth noting that Pd(0)/BaCO 3 is not a commonly used catalyst for C À C bond formation and Pd(0)/CaCO 3 has been rarely used for Suzuki-Miyaura, [8] Stille [9] and Heck [10] reactions. Finally, in terms of safety issues, Pd(0)/BaCO 3 should be much more appropriate for large-scale coupling than dry Pd/C, for which the selfignition in the presence of methanol and oxygen could be a major concern.…”

Facile and Efficient Reductive Homocoupling of Benzyl and Aryl Halides Catalyzed by Ionic Liquid [C12mim][CuCl2] in the Presence of Metallic Zinc and Copper

“…The usual synthetic methods for such a conversion include the Ullmann coupling [4][5][6], Suzuki coupling [7][8][9][10][11][12], Scholl reaction [13,14], Gomberg-Bachmann reaction [15,16], Stille reaction [17][18][19][20], and other couplings [21][22][23][24]. However, these above-mentioned protocols, in general, are invariably associated with one or more disadvantages, such as low yields, long reaction times, high reaction temperatures, high catalyst loading, tedious workup procedures, costly metal catalysts, difficulty of catalyst recovery, and environmental toxicity.…”