Diad Phosphorus-Nitrogen Prototropism of Tris(alkylamino)phosphines

摘要

We found that tris(alkylamino)phosphies I exist in a tautomeic prototropic equilibrium with PH-iminophosphoranes II. The diad phosphorus-nitrogen prototropism of tris(alkylamino)phosphines has not been previously reported, though the attemped synthesis of compounds I has been reported by Michaelis. However, a conclusion has been made that these compounds are unstable, which is probably explains the fact that they remained unexplored until now. PH-Iminophosphoranes with strong electron-acceptor substituents of nitrogen (sulfonyl, acyl, silyl) have only been described. From this point of view, tris(trialkylamino)phosphines I containing the electrondonor alkyl groups on nitrogen present undoubtful theoretical interest, and their prototropism can be regarded as an independent type of diad phosphorusnitrogen tautomerism.