Selective Oxidative Scission of Olefins to Aldehydes Enabled by Ruthenium Complexes Containing Salicylaldimine Ligands

ABSTRACT Treatment of Ru 3 (CO) 12 with salicylaldimine ligands [ArNCH(3‐ t BuC 6 H 3 OH) [ArC 6 H 5 ( L1H ); 4‐OMeC 6 H 4 ( L2H ); 4‐MeC 6 H 4 ( L3H ); 2,4,6‐Me 3 C 6 H 2 ( L4H ); 4‐ClC 6 H 4 ( L5H ); 4‐BrC 6 H 4 ( L6H )] in refluxing toluene afforded six bis‐ligand mononuclear ruthenium carbonyl complexes [ArNCH(3‐ t BuC 6 H 3 O)] 2 Ru(CO) 2 1a – 1f in good yields. All of the Ru(II) complexes were characterized using IR, NMR, and elemental analysis. The molecular structures of complexes 1a , 1b , 1e , and 1f were further confirmed through X‐ray diffraction analysis. Additionally, the catalytic performance of these complexes was investigated in the oxidation of olefins to aldehydes, using TBHP as the oxidant in refluxing trichloromethane. With 1.0 mol% catalyst loading, these ruthenium complexes displayed high reactivity and good functional‐group compatibility, selectivity providing the corresponding oxidation product aldehydes in 73%–94% yields.