Nickel-Catalyzed Negishi Cross-Coupling Reactions of Secondary Alkylzinc Halides and Aryl Iodides

Abstract

A general Ni-catalyzed process for the cross-coupling of secondary alkylzinc halides and aryl/heteroaryl iodides has been developed. This is the first process to overcome the isomerization and β-hydride elimination problems that are associated with the use of secondary nucleophiles, and that have limited the analogous Pd-catalyzed systems. The impact of salt additives was also investigated. It was found that the presence of LiBF(4) dramatically improves both isomeric retention and yield for challenging substrates.

Exploring Mechanisms in Ni Terpyridine Catalyzed C–C Cross-Coupling Reactions—A Review

“…An earlier study using [Ni(glyme)Cl 2 ] (glyme = ethyleneglycoldimethylether) and various bi-and tridentate aromatic imine ligands as catalysts systems for the Negishi-type cross-coupling of secondary alkylzinc halides and aryl/heteroaryl iodides also found terpyridines superior to bidentate bpy or phen ligands, but also slightly better than the tridentate 2,6-di(1H-pyrazol-1-yl)pyridine, with the exception of the 4 -NO 2 -and 4 -CF 3 -tpy derivatives [63]. This indicates that the redox potentials of the various Ni-tpy species are important, which is in line with our observations.…”

Enabling the Cross-Coupling of Tertiary Organoboron Nucleophiles through Radical-Mediated Alkyl Transfer

“…Representative ligands from the Ni cross-coupling literature ranging from phosphines, 18 pyridines, 19 terpyridines, 20 amino alcohols, 21 N -heterocyclic carbenes, 6 olefins, 22 to 1,3-diketones 23 were all introduced to both a Ni(0) and Ni(II) source in parallel. The reactions were then followed by UPLC to observe the desired coupling product (see Supporting Information for full details).…”

Cross‐Coupling Arylations: Precedents and Rapid HistoricalReview of the Field

“…In 2011, Joshi-Pangu et al [176] reported a very successful nickel-catalyzed Negishi-Baba coupling of secondary alkylzinc halides and aryl iodides (Scheme 1.54). This group has presented the first process that overcomes the isomerization and β-hydride elimination problems that are associated with the use of secondary nucleophiles, and that have limited the equivalent Pd-catalyzed reactions.…”