Mechanistic Studies of Pd(II)-Catalyzed <i>E</i> / <i>Z</i> Isomerization of Unactivated Alkenes: Evidence for a Monometallic Nucleopalladation Pathway
Rei Matsuura, Malkanthi K. Karunananda, Mingyu Liu, Nhi Nguyen, Donna G. Blackmond, Keary M. Engle
Abstract
Pd(II)-catalyzed E/Z isomerization of alkenes is a common process, yet its mechanism remains largely uncharacterized, particularly with nonconjugated alkenes. In this work, the mechanism of Pd(II)-catalyzed E/Z isomerization of unactivated olefins containing an aminoquinoline-based amide directing group is probed using in situ kinetic analysis, spectroscopic studies, kinetic modeling, and density functional theory (DFT) calculations. The directing group allows for stabilization and monitoring of previously undetectable intermediates. Collectively, the data are consistent with isomerization occurring through a monometallic nucleopalladation mechanism.