A wide range of N, O-bis-acylated hydroxylamine derivatives with chloro or arenesulfonyl leaving groups, and a related set of N-hydroxy-N-acylsulfonamides, have been synthesized and evaluated for nitroxyl (HNO) production. Mechanistic studies have revealed that the observed aqueous chemistry is more complicated than originally anticipated, and have been used to develop a new series of efficient HNO precursors (4u–4x, 7c–7d) with tunable half ...