Kinetics and Mechanism of PPh₃/Ni-Catalyzed, Zn-Mediated, Aryl Chloride Homocoupling: Antagonistic Effects of ZnCl₂/Cl^.

ABSTRACT: The Ni/PPh₃-catalyzed homocoupling of aryl chlorides in DMF using Zn as the stochiometric reducing agent is one of a general class of Ni-catalyzed processes, where the mechanism has been a matter of long-standing debate. This study re-evaluates prior conclusions and insights. NMR spectroscopy is used to identify [(PPh₃)₂Ni^II(Ar)Cl] as a key intermediate and to explore the indirect roles of using Zn as the reductant. The [ZnCl₂] coproduct is responsible for several features, including a sequential transmetalation pathway involving [ArZnCl]. [ZnCl₂] also abstracts halide from [(PPh₃)₂NiCl₂] to generate [Ni^IICl(DMF)₅]⁺[ZnCl₃(DMF)]^-, and in d

SUBMITTER: Fohn NA 

PROVIDER: S-EPMC11528415 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature