Six new rhodium-tetrahydropyrimidin-2-ylidene complexes (2a–f) have been prepared and characterized by C, H, N analysis, 1H NMR and 13C NMR. Phenylboronic acid reacts with aldehydes in the presence of a catalytic amount of the new rhodium (I)-carbene complexes, RhCl (COD)(1, 3-dialkyl-3, 4, 5, 6-tetrahydropyrimidin-2-ylidene),(2a–f), to give the corresponding secondary aryl alcohols in good yields (72–96%).