Palladium-catalyzed ligand-free and efficient Suzuki--Miyaura reaction of $N$-methyliminodiacetic acid boronates in water

A green and efficient protocol has been developed for the Pd(OAc)$_{2}$-catalyzed ligand-free Suzuki--Miyaura reaction of $N$-methyliminodiacetic acid (MIDA) boronates in water. In the presence of Pd(OAc)$_{2}$ as a catalyst and ($i$-Pr)$_{2}$NH as a base, the cross-coupling reactions of aryl bromides with aryl MIDA boronates proceeded smoothly in water without any surfactant, and various functional groups were tolerated under the optimized conditions.