Nhydroxy

N-hydroxy refers to a functional group in which a hydroxyl group is bound to nitrogen. The general motif is an N–OH substituent attached to an organic moiety, commonly written as R–NHOH for simple N-hydroxyamines. When the N–OH group is part of a carbonyl compound, the resulting class is hydroxamic acids, represented as R-CO-NHOH, where the nitrogen is bonded to both a carbonyl carbon and a hydroxyl group.

N-hydroxy compounds arise by the hydroxylation or oxidation of amines or amides. They can be prepared by N-hydroxylation using specialized reagents such as hydroxylamine derivatives or other oxidants that introduce the N–OH bond. The N–OH moiety can influence reactivity, including hydrogen bonding and susceptibility to further oxidation, and the exact substituents around nitrogen determine stability and properties.

Hydroxamic acids are a prominent and well-studied class of N-hydroxy compounds. They act as strong chelating ligands for metal ions and have substantial roles in medicinal chemistry, including as histone deacetylase inhibitors such as vorinostat (SAHA). N-hydroxyphthalimide (NHPI) is another notable example, widely used as a mediator in radical oxidation and as a synthetic reagent. N-hydroxy groups also feature in various enzyme inhibitors and natural products.

Safety and handling: N-hydroxy compounds can be oxidizable or reactive, and some may present hazards upon decomposition or exposure. Standard chemical hygiene practices should be followed during storage and use.

See also: Hydroxylamine; Hydroxamic acid; N-hydroxyphthalimide.