Buchwald palladacycle precatalyst with new biaryl(dialkyl)phosphine ligand, VPhos, has an improved activity profile for the reductive coupling of non-aromatic heterocyclic alkyl bromides. Its combined use with a surfactant system of octanoic acid/sodium octanoate enables Negishi coupling and access to diverse C(sp
3)–C(sp
2) cross-coupled products.
It is a fourth-generation (G4)
Buchwald precatalysts are similar to the third generation (G3) precatalysts except that the amino group on the biphenyl backbone is methylated. This modification helps to prevent the limitations of using the third generation precatalysts. It is air-, moisture-, and thermally stable and shows good solubility in common organic solvents.
