Synthesis and catalytic activity of palladium complexes of 8-(pyridin-2-ylmethoxy)quinolinone (3) were investigated. Complexation of 3 with [Pd(CH 3 CN) 2 Cl 2 ] gave the dimeric palladium complex [{N,N-(3)PdCl} 2 ] (4). The structure of 4 was characterized by 1 H/ 13 C NMR spectroscopy and mass spectrometry, and further confirmed by X-ray crystallography. Complex [a] 5449 4 acts as a catalyst for oxidative cleavage of C=C bonds, and it catalyzes the hydration of styrenes in an anti-Markovnikov Wacker manner to give terminal aldehydes as the initial product, which then undergo C-C cleavage to yield the corresponding benzaldehydes. Systematic studies of this catalysis were performed.Scheme 2. Tautomers of 8-hydroxycarbostyril and ligand 3. Results and Discussion Preparation of Palladium ComplexesScheme 3 outlines the synthetic approach leading to the desired ligand 3. Compound 1 was prepared according to a literature procedure. [9] Starting from 8-hydroxyquinoline (2), oxidation and acetylation followed by basic hydrolysis provided 1 in 65 % yield of isolated product. Nucleophilic substitution of 2-(bromomethyl)pyridine with 1 under basic conditions in acetonitrile gave 3 in 82 % yield, which was characterized by IR and NMR spectroscopy and mass spectrometry. The carbonyl stretching band at 1682 cm -1 in the IR spectrum clearly demonstrates the existence of amido functionality. The 1 H NMR spectrum of 3 in CDCl 3 shows a downfield signal at δ = 10.02 ppm corresponding to C(O)NH. The 13 C NMR chemical shift of the carbonyl carbon atom at δ = 162.6 ppm is in agreement with Scheme 3. Preparation of ligand 3.