The Equilibrium NH Acidity of Organic Compounds

The literature data of the last decade on the acidity of the N–H bond in organic compounds in aprotic solvents and in the gas phase are examined. The influence of structural factors on the equilibrium NH acidities of arylamines, carboxamides, sulphonamides, polyfluoroaryl compounds, and heterocycles, as well as the acidifying effects of the electron-accepting substituents at the NH acid centre are discussed on the basis of the results of studies of protolytic equilibria in dimethyl sulphoxide. The question of the influence of the N-anion stabilisation factors in solution (specific solvation and ion association) on the relative strengths of NH acids is also considered. Data obtained in studies of the NH acidity in the gas phase are presented.
The bibliography includes 103 references.