Kinetic Study of the Herrmann–Beller Palladacycle-Catalyzed Suzuki–Miyaura Coupling of 4-Iodoacetophenone and Phenylboronic Acid

Abstract

This article presents an experimental kinetic study of the Suzuki–Miyaura reaction of 4-iodoacetophenone with phenylboronic acid catalyzed by the Herrmann–Beller palladacycle. This catalyst, together with the solvent (ethanol) and the base (sodium methylate), were chosen to ensure catalyst stability and reactants solubility all along the reaction. Based on the study of initial reaction rates, a quasi-first-order was found for 4-iodoacetophenone with a first-order dependence on the initial concentration of palladium. A zero-order was found for the base and the phenylboronic acid. The oxidative addition step of the mechanism was thus considered as the rate determining step. A global rate law was derived and validated quantitatively. A global activation energy, with an average value of ca. 63 kJ/mol was determined.

Micelle-Derived Palladium Nanoparticles for Suzuki–Miyaura Coupling Reactions in Water at Room Temperature

“…The concentration of Pd was varied between 0.0025 and 0.001 M at a constant substrate concentration and temperature. According to Figure c, the initial reaction rate was first order with respect to the initial Pd concentration, which is consistent with the previous report . The effect of temperature on the Suzuki reaction was studied by varying the temperature from 15 to 45 °C, with the other optimal reaction parameters being kept constant (Figure d).…”

“…According to Figure 5c, the initial reaction rate was first order with respect to the initial Pd concentration, which is consistent with the previous report. 74 The effect of temperature on the Suzuki reaction was studied by varying the temperature from 15 to 45 °C, with the other optimal reaction parameters being kept constant (Figure 5d). As expected, the reaction conversion and reaction rate increased with the rise of temperature.…”

Open cell foam materials as Pd reservoirs for Suzuki–Miyaura coupling catalysis at ppb level

“…To further quantify this deactivation phenomenon, kinetic constants were evaluated, based on the hypothesis that the kinetic model established for the Suzuki–Miyaura coupling with a palladacycle homogeneous catalyst would be the same for the leached active species. 20 r = k [ArI][Pd] where [ArI] is the concentration of the aryl halide and [Pd] is the Pd concentration in the liquid (leached species). A concentration of 30 ppb was used for the estimation.…”

Easy preparation of small crystalline Pd2Sn nanoparticles in solution at room temperature

“…The experimental conditions (nature of the base and solvent, number of equivalents of reagents, and temperature) were chosen based on a literature precedent which had opti-mized such parameters. 46 The conversions and yields were determined by GC (see the ESI † for representative chromatograms) and blank experiments without a catalyst were conducted to ensure the catalytic performances of these NPs. Importantly, Pd NPs prepared in toluene or THF exhibited the same activity and TON, showing the absence of solvent effect.…”