A. I. Albanov

Synthesis and relative stability of five- and six-membered S-functional derivatives of 1,3-thiasilacycloalkanes

Abstract Oxidation, imidation, and S -methylation reactions of five- and six-membered 1,3-thiasilacycloalkanes have been examined under various conditions. The S -functional derivatives of 1,3-thiasilacycloalkanes undergo solvolytic SiC(S) bond cleavage in protic media. The ease of the ring opening depends on the S -functionality and on the ring size.

Highly unsaturated macrocyclic silicohydrocarbons

Abstract Nineteen 12-, 15-, 18-, 24- and 30-membered, highly unsaturated macrocyclic silicohydrocarbons containing -SiCCSi-, (E)-SiCHCHSi- and -SiCH2CH2Si-fragments in the ring were synthesized by the reaction of Me2Si(CCMgBr)2 or BrMgCCMe2SiCCSiMe2CCMgBr with FMe2SiCH2CH2SiMe2F; (E)-FMe2SiCHCHSiMe2F or (E, E)-(ClMe2SiCHCH)2SiMe2; (E)-BrMgCCMe2Si-CHCHSiMe2CCMgBr or Me2Si(CCSiMe2CCMgBr)2 with (E, E)-(ClMe2SiCHCH)2SiMe2; and Me2Si(CCSiMe2CCMgBr)2, BrMgCCMe2-SiCCSiMe2CCSiMe2CCSiMe2CCMgBr or BrMgCCMgBr with (E)-FMe2SiCH  CHSiMe2F under conditions of high dilution. Two 20-membered and one 26-membered macrocyclic silicohydrocarbons containing 6 or 8 silicon atoms bonded by 6 or 8 CC bonds and an endocyclic CH2CH2 or CHCH bridge were obtained for the first time by treating BrMgCCMe2SiCCSiMe2CCMgBr with Cl2MeSiCH2CH2SiMeCl2 or (E)-F2MeSiCHCHSiMeF2, as well as Me2Si(CCSiMe2CCMgBr)2 with (E)-F2MeSiCHCHSiMeF2.

NMR study of C- and N-trimethylsilylazole derivatives

C‐ and N‐trimethylsilylazole derivatives were studied by 1H, 13C and 29Si NMR spectroscopy. Degenerated prototropic tautomerism of 4‐trimethylsilylpyrazole in methanol and the silylotropy of 1‐trimethylsilyl‐4‐methylpyrazole in a neat liquid were investigated for the first time. 3‐ and 5‐tautomers of 3(5)‐methylpyrazole in a ratio of 54:46 were found in methanol by use 13C NMR spectroscopy (Tc=230 K, ΔGc≠=10 kcal mol‐1).

Vicarious C-amination of 1-methyl-4-nitroimidazole

A one electron transfer process during the vicarious nucleophilic substitution C-amination of 1-methyl-4-nitroimidazole is detected by EPR-monitoring.

O,O-dialkyl-S-(1-silatranylalkyl) dithiophosphates

ConclusionsThe reactions of 1-(3-chloropropyl)silatrane with potassium O,O-diethyl dithiophosphate gave O,O-diethyl-S-(1-silatranylpropyl) dithiophosphate. O,O-Diethyl- and O,O-dipropyl-S-(1-silatranylmethyl) dithiophosphates were synthesized by the tranesterification of O,O-diethyl-and O,O-dipropyl-S-(trimethoxysilylmethyl) dithiophosphates by tris(2-hydroxyethyl)amine.

Synthesis of acyclic α- and β-silyl sulfimides

Conversion of acyclic α- and β-silyl sulfides by their treatment with sodium salts of N-chlorosulfonamides into the corresponding previously unknown sulfimides is described. The process is accompanied by a competing reaction resulting in the formation of α- or β-silyl sulfoxides. β-Silyl sulfimide (9b) undergoes thermolysis to generate trimethylvinylsilane.

1-phenyl-4,4-dimethyl-1,4-phosphasilacyclohexane and its selenide

Conclusions1.1-Phenyl-4,4-dimethyl-1,4-phosphasilacyclohexane was formed upon the photochemical addition of phenylphosphine to dimethyl(divinyl)silane and gave 1-phenyl-4,4-dimethyl-1-seleno-1,4-phosphasilacyclohexane upon reaction with elemental selenium.2.NMR spectroscopy indicated that 1-phenyl-4,4-dimethyl-1,4-phosphasilacyclohexane and 1-phenyl-4,4-dimethyl-1-seleno-1,4-phosphasilacyclohexane exist in the chair conformation with predominance of the conformer with axial orientation of the unshared electron pair of the phosphorus atom.

4-Phenyl-1,4-thiaphosphorinane and its selenide

ConclusionsPhotochemical addition of phenylphosphine to divinylsulfide gave a low yield of 4-phenyl-1,4-thiaphosphorinane. Reaction of the latter with elemental selenium led to a quantitative yield of 4-phenyl–4-seleno-1,4-thiaphosphorinane.