Study of homo- and cross-coupling competition in the reaction of triarylbismuth(V) dicarboxylates with methyl acrylate in the presence of a palladium catalyst

C–C Coupling Reaction of Triphenylbismuth(V) Derivatives and Olefins in the Presence of Palladium Nanoparticles Immobilized in Spherical Polyelectrolyte Brushes

“…Because classic Heck-type reactions usually require the presence of a base, we tested its influence in the reaction. As previously observed for homogeneous catalyst systems in organobismuth C-C coupling reactions, [20] the addition of a base into the reaction mixture decreases the reactivity of the substrate. When tBuOK was omitted from the reaction mixture, the yield of transstilbene increased from 3 to 7 % and the yield of biphenyl increased from 49 to 68 % (Table 1, Entries 1, 2).…”

“…[20] Comparison of this catalyst system with Pd@SPB reveals a high degree of similarity in terms of the product selectivity. To solidify these similarities, we used [Pd(cod)Cl 2 ] as a catalyst and a catalyst loading similar to those used for other homogeneous systems, and the substrates were coupled with the Pd@SPB catalyst system.…”

“…Possible reaction pathways of this reaction by using molecular palladium catalysts were recently described. [20] The C-arylation reaction of ethyl acrylate with tris(para-tolyl)bismuth bis(trifluoroacetate), p- The formation of the Heck-type products (Figure 1) proceeds with an initial rate of 8.9 mmol l -1 h -1 and the forma-tion of the bitoluyl byproduct with an initial rate of around 2.7 mmol l -1 h -1 . This means that the initial formation of the Heck-type product is around three times faster than biaryl formation.…”

“…[2,3] This research is directed towards finding more reactive substrates and milder procedures that would allow for a base-free arylation. It was shown that different organometallic derivatives such as boronic acids, [4][5][6][7][8] arylsilanols, [9] arylstannanes, [10] aryltellurides, [11][12][13] organolead, [14] organoantimony, [15][16][17][18][19] and organobismuth [20] derivatives can be used to form Heck-type products.…”

“…by the one-step reaction of triphenylbismuth with the appropriate carboxylic acid in the presence of equimolar amounts of peroxide. [20,32] Scheme 2 shows the structure of the spherical polyelectrolyte brushes (SPB) in a schematic manner: Long polyelectrolyte chains with quaternized amino groups were chemically grafted onto the colloidal polymer particles with diameters of ca. 100 nm.…”