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.
Highlights
The Suzuki–Miyaura (SM) reaction, and more generally Pd carbon–carbon (C-C) cross-coupling reactions, have been the subject of numerous and prolific research in organic chemistry and catalysis [1]crowned by the 2010 Nobel Prize for Chemistry [2,3,4,5], awarded to Richard Heck, Ei-ichi Negishi, andAkira Suzuki
Despite the interest devoted to the mechanism and, more generally, to the reaction [1], very few publications provide global kinetic data and/or rate laws
The quantitative impacts of the different protagonists—catalyst, arylhalide, boronic acid, base, and temperature—are seldom available in a single rate law, albeit such impacts would be highly valuable for the design of production processes
Summary
The Suzuki–Miyaura (SM) reaction, and more generally Pd carbon–carbon (C-C) cross-coupling reactions, have been the subject of numerous and prolific research in organic chemistry and catalysis [1]crowned by the 2010 Nobel Prize for Chemistry [2,3,4,5], awarded to Richard Heck, Ei-ichi Negishi, andAkira Suzuki. Many authors have shown an interest in the mechanism [6,7,8,9,10,11,12,13,14], proposing different mechanisms that have the same basic elementary steps, but with detailed discussions about several key points such as the nature of the active species [7,12,15], the role of the base [16,17,18], the missing links in the transmetallation step [19], the rate-limiting step, and the solvent effect [14]. The quantitative impacts of the different protagonists—catalyst, arylhalide, boronic acid, base, and temperature—are seldom available in a single rate law, albeit such impacts would be highly valuable for the design of production processes. Concerning the base, a very early report of a first-order rate law with respect to NaOH [20]. The reaction order with respect to the arylhalide is controversial. The quantitative temperature effect on the SM reaction was Catalysts 2020, 10, 989; doi:10.3390/catal10090989 www.mdpi.com/journal/catalysts
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
