Halodioxoruthenate(VI) complexes as catalysts for the oxidation of alcohols

The new salts trans -(R-pyH) 2 [RuO 2 Cl 4 ] (R-py = pyridine and substituted pyridines), trans -R 2 [RuO 2 X 4 ] [X = Cl, Br; R = Me 2 NH(CH 2 ) 2 NHMe 2 , Me 2 N(C 2 H 4 ) 2 NMe 2 ]; (Ph 4 P)[RuO 2 Br 3 ], trans -(Ph 4 P) 2 [RuO 2 Br 4 ] and trans -(Ph 4 As)[RuO 2 Cl 3 (OPPh 3 )] are reported. They function in dichloromethane or acetonitrile as two-electron catalysts for the oxidation of primary alcohols to aldehydes and of secondary alcohols to ketones, without competing olefinic bond cleavage, in the presence of N-methylmorpholine-N-oxide as co-oxidant. Vibrational spectra of the complexes are reported.