Acetimidic

Acetimidic is an adjective used in organic chemistry to describe things related to acetimidic acid or to derivatives of that acid. Acetimidic acid refers to the imidic acid tautomer of acetamide, and it is typically represented by the structure CH3-C(=NH)OH. In solution, this tautomer can be in equilibrium with acetamide, and the term is most often encountered in discussions of tautomerism and related reactivity. The defining structural motif is the imidoyl group C(=NH)–, which can bear various substituents on the oxygen to form acetimidate derivatives.

Acetimidate esters have the general form R-C(=NH)OR', where the hydroxyl component is alkylated or arylated. These acetimidate derivatives are widely used in organic synthesis, notably in carbohydrate chemistry, where glycosyl donors such as glycosyl acetimidates and related trichloroacetimidates serve as activated reagents for glycosidic bond formation. In these applications, the acetimidate group acts as a leaving group under Lewis acid catalysis, facilitating the generation of reactive glycosyl oxocarbenium ions.

In broader contexts, the term acetimidic appears primarily in specialized literature concerned with imidic acids, imidates, and acetimidoyl chemistry. It denotes the family of compounds that contain the acetimidoyl/imidalidic motif and participate in protection, activation, or formation steps in synthetic sequences. See also imidic acid, imidate, glycosyl donor, and trichloroacetimidate.