Isotope Effects Reveal the Catalytic Mechanism of the Archetypical Suzuki-Miyaura Reaction
Year: 2022
Type: article
Abstract: : Experimental and theoretical 13C kinetic isotope effects are utilized to obtain atomistic insight into the catalytic mechanism of the Pd(PPh3)4 catalyzed Suzuki-Miyaura reaction of aryl halides and aryl boronic acids. Under catalytic conditions, we establish that oxidative addition of aryl bromides occurs to a 12-electron monoligated palladium complex (Pd(PPh3)). For aryl iodides, the first irreversible step in the catalytic cycle precedes oxidative addition and is shown to be binding of the iodoarene to Pd(PPh3). Our results suggest that the commonly proposed oxidative addition to the 14-electron Pd(PPh3)2 complex can occur only in the presence of excess added ligand or under stoichiometric conditions. The transmetalation step, under catalytic conditions, is shown to proceed via a tetracoordinate boronate (8B4) intermediate with a Pd-O-B linkage.
Source: ACS Catalysis
Institution: Binghamton University
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
Awards: G1742171491, G2206590661, G2356321744, G2722810353, G309578167, G3147773666, G3226045097, XSEDE 2.0: Integrating, Enabling and Enhancing National Cyberinfrastructure with Expanding Community Involvement, Mechanistic Investigation into Photoredox Catalysis, G7007390191, G7320324764, Novel Concepts and Mechanistic Probes in Catalysis, G8323970022, 400 MHz NMR Spectrometer for Regional NMR Facility, Mechanistic Studies at the Frontiers of Catalysis
OpenAlex ID: W4212999072