T. M. Shcherbina

REACTION OF 2,6-DIBENZYLIDENECYCLOHEXANONE WITH PHOSPHORUS PENTACHLORIDE :TRIPLE FUNCTIONALIZATION OF THE ISOSEMIQUINOID SYSTEM

The reaction of 2,6-dibenzylidenecyclohexanone with PCl5 occursvia the sequential stages of desoxychlorination and substitutional phosphorylation to form (after oxidation, methoxylation, and hydrolysis on the surface of the chromatographic SiO2 adsorbent) organophosphorus products of the 1-(a-chloro-, a-hydroxy-, or α-alkoxy)benzyl-2-chloro-3-(α-(dimethylphosphoryl)benzylidene)cyclobex-1-ene series.

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. 17. Synthesis and the stereochemistry of tris(α-trifluoromethylbenzyl) phosphates

Catalytic phosphorylation of α-trifluoromethylbenzyl alcohols with POCl3 taken in a ratio of 3 : 1 under particular temperature conditions afforded predominantly symmetrical tris(α-trifluoromethylbenzyl) phosphates. The latter were obtained as mixtures of two diastereomers with a statistical ratio of the components.

α-Polyfluroalkylbenzyl dichlorophosphates as alkylating agents in alkylation of aromatic compounds

On heating, α-polyfluoroalkylbenzyl dichlorophosphates alkylate mesitylene, durene, and naphthalene to give the corresponding aromatic compounds containing the α-polyfluoro-alkylbenzyl fragment as a substituent.

Synthesis and thermal stability of silicon-containing esters of phosphorus acids

A number of trialkylsilylmethyl diphenyl phosphates MeRR′SiCH2OP(O)(OPh)2 (1a-e: R=Et (a), Pr (b), CF3CH2CH2 (c, e), Me3SiCH2 (d); R′=Me (a-d), Et (e)) were synthesized and their thermal rearrangement, of the 1,2-shift type, was studied. The rearrangement consists of the migration of an alkyl group from Si atom to the methylene carbon atom and gives the corresponding silyl esters. The rate of the rearrangement was found to increase in the order1d<1b<1a<1 (R=R′=Me)<1c corresponding to the enhancement of the total inductive effect (−I) of the substituents at the Si atom. The relative migration ability of the substituents at the Si atom, determined by GC/MS analysis of the disiloxane fraction resulting from hydrolysis of pyrolyzed phosphates1a-e, increases in the order R=Pr<Et<CF3CH2CH2<Me≪Me3SiCH2, which differs substantially from the order in which the rate of the rearrangement of phosphates1a-d changes. The electronegativity of the migrating group affects noticeably the relative ability to migrate.

A GC-MS INVESTIGATION OF THE MECHANISM OF IMIDE-AMIDE REARRANGEMENT

The products of imide-amide rearangement of trialkyl (arylimido)phosphates were studied by the GC-MS method. An ionic chain mechanism was suggested for this reaction.

Imide-amide rearrangement under the influence of boron trifluoride etherate

Conclusions1.Reaction of triethyl N-phenyl-phosphorimidate with BF3 etherate yields a complex of 0,0-diethyl-N-ethyl-N-phenyl-phosphoramidate with BF3.2.The31P and19F NMR spectra of the complexes of 0,0-diethyl-N-ethyl-N-phenyl-phosphoramidate and 0,0-diethyl-N,N-diethyl-phosphoramidate with BF3 have been studied, and JP−F coupling through the P=0·BF3 coordination bond has been detected.3.It has been discovered that trialkyl N-aryl-phosphorimidates undergo imide-amide rearrangement under the influence of catalytic amounts of BF3 etherate.

Synthesis of trialkyl (dialkoxyphosphorylimido)phosphates

Conclusions(Dichlorophosphorylimido)phosphorus trichloride reacts with sodium alcoholates in the corresponding alcohol as the medium to give trialkyl (dialkoxyphosphorylimido)phosphates in 40–90% yield.