Design, Synthesis, Structure, and Dehydrogenation Reactivity of a Water-Soluble o-Iodoxybenzoic Acid Derivative Bearing a Trimethylammonium Group

5-Trimethylammonio-1,3-dioxo-1,3-dihydro-1λ5-benzo[d][1,2]iodoxol-1-ol anion (AIBX 1a), an o-iodoxybenzoic acid (IBX) derivative having the trimethylammonium moiety on its phenyl ring, possesses very good solubility in water and distinct oxidative properties from IBX, which is demonstrated in the oxidation of various β-keto esters to the corresponding dehydrogenated products using water as cosolvent. The regeneration of AIBX 1a can be easily realized from the reaction mixture due to its good water solubility.