[RuCl2(p-cymene)]2-catalyzed conjugate addition of arylboronic acids to α,β-unsaturated ketones under ligand-free and neutral conditions.

A simple and efficient Ru-catalyzed conjugate addition reaction of arylboronic acids to α,β-unsaturated ketones under neutral conditions without any additional ligands has been developed. This Ru(II)-catalytic system both fulfilled the inhibition of the β-hydride elimination in the catalytic cycle and minimized the protonolysis of arylboronic acids.