Nickel/β‐CD‐catalyzed Suzuki–Miyaura cross‐coupling of aryl boronic acids with aryl halides in water.

In this study, a convenient nickel‐catalyzed protocol has been introduced for the Suzuki–Miyaura coupling reaction. A simple mixture of Ni(II) and unfunctionalized β‐cyclodextrin (β‐CD) was used to cross‐coupling of aryl halides with aryl boronic acids for the synthesis of biaryls in water. β‐CD is a water‐soluble seminatural cyclic oligosaccharide, environmentally friendly biomaterial, inexpensive, and commercially available ligand. This ligand with low solubility in usual organic solvents has been used for the synthesis of biaryls in good to excellent yields. The cross‐coupling results in the presence of Ni(II)/β‐CD catalytic system showed that the coupling reaction carried out with appropriate yields for both electron‐rich and electron‐deficient aryl halides. The coupling reaction completed in water as a green solvent. The catalyst was also recycled for four runs with a small decrease in its catalytic activity. The presented new method allows an easier and more cost‐efficient synthesis of biaryls from the reaction of arylboronic acids with various aryl halides in water. [ABSTRACT FROM AUTHOR]