I. Yu. Kudryavtsev

CATALYTIC ACTIVITY OF VARIOUS LEWIS ACIDS IN THE PHOSPHORYLATION OF PRIMARY POLYFLUOROALKANOLS WITH PHOSPHORYL CHLORIDE

The catalytic activity of SnCl2, SnCl4, SbCl3, SbCl5, and BiCl3 in the reaction of 2,2,3,3,4,4,4-heptafluoroubutanol with POCl3 was studied. The mechanism of this reaction is discussed. Strong Lewis acids were found to be less active catalysts.

Dissociation constants for polyfluoro acids of phosphorus in various media

Conclusions1.Various polyfluoro acids of phosphorus have been synthesized. Potentiometric titration in transference cells has been used to determine the dissociation constants of these acids in nitromethane and in 50, 80, 95, and 100% alcohol solutions.2.The differences in strength of the polyfluoro acids of phosphorus tend to be minimal in aqueous alcoholic solution.3.The spectral characteristic (ΔνOH) of the H-bonds of phenol-polyfluorophosphoryl complexes have been measured in CCl4 solution.4.The σФ values of polyfluoroalkoxyl substituents are radically different in aqueous and in water-free solvents. The companion values for 3,3,3-trifluoropropoxy and 3,3,3-trifluoropropyl groups are not affected by changes in the solvent.

Silicon-induced diastereoselectivity of the catalyzed phosphorylation of 1-(perfluoroalkyl)-ω-(trialkylsilyl)alkan-1-ols

The stereochemistry of catalytic phosphorylation of 1-(perfluoroalkyl)-ω-(trialkylsilyl)alkan-1-ols with pentavalent phosphorus acid monochlorides (phosphonochloridates, methyl(phenyl)phosphinic chloride, and phosphorochloridates) was studied. The effects of the structures of alcohols and phosphorylating agents on the degree of the reaction diastereoselectivity were investigated. Methylphosphonochloridates were found to react most stereoselectively; the diastereoselectivity of the phosphorylation is independent of the donor or acceptor character of substituents at the phosphorus atom, being determined by their volumes. In the series of silylalkanols, the diastereoselectivity of the reaction the higher the closer the Si atom to the reactive site of the molecule, the larger the volume of the perfluoroalkyl substituent, and the more pronounced the electron-withdrawing properties of the substituents at the Si atom. A reaction mechanism is proposed that rationalizes the stereoselectivity of the reaction.

Catalytic phosphorylation of polyfluoroalkanols 13. Some ammonium and phosphonium salts as phosphorylation catalysts

It was shown that it is possible to use a series of ammonium and phosphonium salts as effective catalysts for the preparative synthesis of tris(polyfluoroalkyl) phosphates. The effect of the structure of substituted ammonium salts on their catalytic activity was studied in the phosphorylation of 1,1-dihydroperfluorobutanol by phosphorus oxychloride. It was determined that the reaction rate is affected not only by the solubility of the salt, but also by the nature of the ion pair and the steric access of the onium center for solvation by phosphoryl compounds.

Catalytic phosphorylation of polyfluoroalkanols. 11. α-Polyfluoroalkylbenzyldichlorophosphates as phosphorylating agents in the catalytic phosphorylation of primary polyfluoroalkanols

Conclusionsα-Polyfluoroalkylbenzyldichlorophosphates react, in the presence of catalytic quantities of certain metals or their salts, with polyfluorinated primary alcohols with the formation of phosphorylation products [bis(polyfluoroalkyl)(α-polyfluoroalkylbenzyl)phosphates] exclusively.