ACYLATION OF PHOSPHORYL-ACETONITRILE AND THIOPHOSPHORYLACETONITRILE UNDER PHASE-TRANSFER CATALYSIS CONDITIONS AND THE KETO-ENOL-TAUTOMERISMOF PHOSPHORUS-SUBSTITUTED ACYLACETONITRILES

A procedure was developed for acylation of phosphoryl- and thiophospho rylacetonitriles under phase transfer catalysis conditions. The reacti on in the solid KOH/MeCN system afforded C-acylation products in high yields. fn the individual state and in aprotic solvents, these product s exist in the enol form (Z isomer;) stabilized via a strong intramole cular hydrogen bond. In hydroxyl-containing media and in aprotic bipol ar solvents, these compounds exist as a mixture of two geometric isome rs (E and Z) of the corresponding enols. In this case, the Z isomer ex ists in two forms, namely, in the cyclic form with an intramolecular h ydrogen bond and in the open form stabilized by intermolecular hydroge n bonds with the solvent. The results of X-ray diffraction analysis of both forms of Z isomers of the compounds containing the phosphoryl an d thiophosphoryl groups are discussed.