Phosphoric monoimidazolides

Alcohols can be phosphorylated to phosphoric diesters by ionic phosphoric monoimidazolides in acetone at temperatures of about 50-60 °C over the course of several hours. These imidazolides are generally prepared by reaction of the appropriate phosphate with CDI (see Section 2.2). Reactions with ethyl, -butyl, w-pentyl, -octyl benzyl alcohol and various other alcohols have also been described.[1]... 

With neutral phosphoric monoimidazolides, which are more reactive than the ionic species the reaction time for phosphorylation of an alcohol is reduced. A one-flask synthesis of unsymmetrical phosphoric diesters from N-( 1,2-dimethylethylenedioxy-phosphoryl)imidazole, prepared from di(l,2-dimethylethylene)pyrophosphate and imidazole, is presented below [103,[11]... 

While monoimidazolides of orthophosphoric acid or its monoester are prepared from the corresponding phosphoric acid and CDI, the imidazolide of the diesterphosphate, because of its lower nucleophilicity, must be prepared by condensation of the corresponding chloride with imidazole [24]... 

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