Organosilicon and organophosphorus compounds with pseudohalide groups

The reactions of alkoxydimethylsilyl cyanides with some tetracoordinated phosphorus chlorides and fluorides were investigated. It was shown that the investigated reactions are realized primarily with the replacement of two halogen atoms by functional groups. The transformations of the phosphorus acid cyanides obtained with metal fluorides were studied.For previous communication, see [1].Institute of Physiologically Active Substances, Russian Academy of Sciences, 142432 Chernogolovka. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 187–191, January, 1992.     

Organosilicon and organophosphorus compounds with pseudohalogen groups. 1. Synthesis of alkoxydimethylsilyl cyanides and their reactions with metal fluorides

Alkoxydimethylsilyl cyanides were synthesized by the exchange reaction of the corresponding alkoxydimethylchlorosilanes with trimethylsilyl cyanide, and also by the reaction of the former compounds with HCN in the presence of triethylamine (the latter method is preferential). Reactions of silyl cyanides with SbF₃ and ZnF₂ were studied. It was found that the reaction of silyl cyanides with SBF₃ leads to the formation of Me₂SiF₂ and the corresponding alkoxydimethylfluorosilanes, which were also obtained by counter-synthesis from alkoxydimethylsilylchlorosilanes and metal fluorides (SbF₃, ZnF₂, CsF). Dimethylfluorosilyl cyanide was obtained by the reaction of silyl cyanides with ZnF₂.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1593–1587, July, 1991.     

Reactions of polyfluoroalkenylsulfenyl chlorides with carbonyl compounds

Polyfluorinated 1-fluoroalk-1-enylsulfenyl chlorides react with ketones RCOCH₂R′ to give unsaturated sulfides. The latter undergo smooth cyclization into 2-alkylidene-1,3-oxathioles in the presence of BF₃·NEt₃. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1770–1773, October, 2000.     

Electronic properties of tricoordinated phosphorus in hexagonal phosphininium compounds and molecular aromaticity

Calculations with B3LYP within quantum chemical density functional theory have been carried out for 1-H-phosphininium cation and a series of 1-R-phosphininium molecules (R=cyclopentadiene, alpha and beta pyrroles, alpha and beta phosphole, C5BH5-- and CH2--). The negative nuclear-independent chemical shift values and the positive aromatic stabilization energies confirm that they are aromatic compounds. In particular, the 1-H-phosphininium cation even exhibits stronger aromatic character than the well-known aromatic phosphinine. The aromatic substituents have strong capability to attract electrons. It is the conjugation and aromaticity that keeps the stability and conformations of the molecules investigated. Owing to the perturbation of the aromatic substituted groups, the predicted large T values and the enlarged HOMO-LUMO gap of the phosphininium cation indicate that these compounds are expected in experiment.     

Reactions ofβ-chloroethyl derivatives of tricoordinated phosphorus acids with 1-nitro-1-propene

Conclusions The reactions of the-chloroethyl derivatives of trivalent phosphorus acids proceed via an ionic intermediate, which, depending on the experimental conditions, is stabilized in the direction of ring closure to give an adduct with a pentacovalent phosphorus atom and the formation of the corresponding unsaturated and (-methyl--nitroethyl)phosphoryl compounds. The liberated-chloroethyl nitrite functions as an oxidizing agent of the starting-chloroethyl derivatives of trivalent phosphorus acids.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1398–1401, June, 1978.The authors thank É. I. Gol'dfarb for taking the³¹P–{¹H} NMDR spectra.     

Sulphur substituted organotin compounds. Part 6. Reactions of mercaptomethyltin compounds with arenesulphenyl chlorides

Reactions between Ph₃SnCH₂SAr and 2-NO₂C₆H₄SC? lead to the formation of 2-(ArSCH₂-6-NO₂C₆H₃SSC₆H₄NO₂-2 via the [2,3]sigmatropic rearrangement of the S-arylthio-sulphonium ylides $\text{C}$H₂$\text{S}\text{+}$(Ar)SC₆H₄NO₂2.     

The syntheses and structures of iron carbonyl adducts of tricoordinated hypervalent phosphorus compounds

The hypervalent phosphorus compound 3,7-di-t-butyl-5-aza-2,8-dioxa-1-phosphabicyclo[3.3.0]octa-2,4,6-triene(ADPO), forms a monosubstituted adduct, ADPO·Fe(CO)₄, by direct reaction of 10-P-3 ADPO with Fe₂(CO)₉ or Fe(CO)₅, as well as by reaction of 1,1-dichloro-3,7-di-t-butyl-5-aza-2,8-dioxa-1-phosphabicyclo[3.3.0]octa-3, 6-diene(ADPO·Cl₂) with Na₂[Fe(CO)₄]. The X-ray crystal structure of ADPO·Fe(CO)₄ shows that ADPO is coordinated to the iron through the phosphorus. The phosphorus of the adduct has a tetrahedral 8-P-4 geometry in contrast to the planar T-shaped geometry of uncomplexed 10-P-3 ADPO. Ultraviolet photolysis of ADPO·Fe(CO)₄ yields the disubstituted species (ADPO)₂·e(CO)₃ wherein ADPO has dimerized via P–O bond cleavage to form a bidentate (ADPO)₂ ligand containing a 10-membered ring that bridges axial and equatorial positions at the trigonal bipyramidal iron center.     

Reactions of hydroxyl groups with tosylchloride-dimethylaminopyridine system. Direct synthesis of chlorides from hydroxycompounds

The reactions of various hydroxyl groups with tosylchloride-dimethylaminopyridine system were investigated and direct syntheses of allyl, alkyl and glycosyl chlorides are described.     

Reactions of compounds containing dicoordinated phosphorus with isocyanates

Conclusions Reaction of 2-acetyl-5-methyl-1,2,3-diazaphosphole with phenyl, trichloroacetyl, anaphthyl, and trimethylsilyl isocyanates gives the 4-substituted diazaphospholes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 169–171, January, 1986.     

Enantiomeric analysis of chiral compounds using phosphorus acid chlorides

New achiral separating bifunctional reagents, dichlorides of methylphosphonic and O-ethyl-thiophophoric acids, have been used for the quantitative determination of the enantiomeric composition of α-amino acids (alanine, valine, proline), secondary alcohols (2-octanol, 2-pentanol, 1-methoxy-2-propanol) and α-phenylethylamine. The determination of the enantiomeric composition of optically active α-amino acids, secondary alcohols, and amines is based on the transformation of compounds into symmetric diastereometers using organophosphorous achiral bifunctional reagents followed by the determination of the derivatives by gas chromatography with a mass spectral detector.