Mechanistically Driven Development of Kumada Catalyst-Transfer Polymerizations: A Rapid Injection NMR Study.

ABSTRACT: Transmetalation is a pivotal step in the Kumada-Tamao-Corriu cross-coupling reaction, yet its mechanistic details have remained relatively unexplored compared to other palladium-catalyzed processes. Herein, we systematically investigate how diverse phosphine ligands influence the transmetalation rate, using rapid injection NMR (RI-NMR) to directly monitor the formation of the cross-coupling product. The study reveals that both ligand electronic and steric effects significantly affect k _obs, with electron-rich ligands tending to slow down the reaction and heteroatom-substituted ligands (CPhos) dramatically accelerating transmetalation. Computational studies suggest that the relatively lower transmetalation transition state barriers for CPhos over SPhos oxidative addition c

SUBMITTER: Kang S 

PROVIDER: S-EPMC12723679 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature