The ruthenium(II) bis(PYA) complex 1 (PYA = p-pyridylidene amide) is a powerful catalyst for the oxidation of sulfides to sulfones, of alkenes to carbonyl compounds, and of terminal alkynes to carboxylic acids by using NaIO4 as the terminal oxidant. The catalytic system shows a broad functional group tolerance and rate differences between alkyne and sulfide oxidation that are sufficiently large to effectively achieve selective sulfide oxidation with exquisite selectivity.