L. V. Zhilitskaya

Alkylation of imidazole and benzimidazole derivatives with 1-(iodomethyl)-1,1,3,3,3-pentamethyldisiloxane – a new method for the preparation of organocyclosiloxane iodides

The reaction of imidazole and benzimidazole derivatives with 1-(iodomethyl)-1,1,3,3,3-pentamethyldisiloxane resulted in N1,3-alkylation, cleavage of siloxane bonds by the evolved hydrogen iodide, and the formation of cyclic organosilicon iodides and triiodides.

Metal polyacrylates, ferrocene derivatives, and polysuccinimide as potential antitumor drugs

Compounds belonging to three novel groups of oncological drugs (metal polyacrylates, ferrocene derivatives, and polysuccinimide) showed antitumor activity. The most efficient compounds, viz., gold polyacrylate (auracryl), 2-[(1-ferrocenylethyl)sulfanyl]pyrimidine (LS-17), and polysuccinimide, inhibit the growth of murine solid tumors by 70–95% and are recommended for further thorough preclinical studies of their antitumor properties and mechanisms of action.

Highly Unsaturated Macrocyclic Organosilicon Compounds

Abstract A series of 12-, 15-, 18-, 21-, 24-, 27- or 30-membered macrocyclic silahydrocarbons of general formula (MeRSiC≡C)n, n=4-10 and R = H, Me, CH2=CH were synthesized by reaction of Me2Si(C≡CMgBr)2, Me(CH2=CH)Si(C≡CMgBr)2, BrMgC≡CMe2SiC≡CSiMe2C≡CMgBr or BrMgC≡CMe,SiC≡CSiMe,C≡CSiMe2C≡CSiMe2C≡CMgBr with MeHSiCl2, Me2SiCl2, Me(CH2=CH)SiCl2 or (ClMe2SiC≡C)2SiMe2. 23-Membered spiromacrocyclic polyacetylenic silahydrocarbons containing 6 silicon atoms, 8 triple bonds and central Si or Ge atoms were prepared by reaction of Me2Si(C≡CSiMe2C≡CMgBr)2 with MC4, (M = Si, Ge).

Binulcear polyunsaturated organosilicon dendrimers

Binuclear polyunsaturated organosilicon dendrimers of the zero and first generations, whose central silicon atoms are linked by-CH2-Ch2-,-CH=CH-, or-C≡C-bridges, and also containing internal (C≡C) and (CH=CH) groups are prepared. NMR spectra of all the compounds obtained are studied. Their molecular weights were calculated and evaluated experimentally. Key parameters of new dendrimers are presented.

New polyunsaturated organosilicon dendrimers based on 1,1-diethynyl-and 1-vinyl-1-ethynylsilacycloalkanes

Abstract1,1-Dichloro-and 1-vinyl-1-chlorosilacyclanes were prepared by reactions of tetrachlorosilane or vinyltrichlorosilane with magnesium and 1,4-dibromobutane or 1,5-dibromopentane. The reactions of the products obtained with ethynylmagnesium bromide or bis(bromomagnesio)acetylene yield the corresponding ethynylsilacyclanes. Condensation of 1,1-diethynylsilacyclanes or bis(ethynylsilacyclopentyl)ethyne with an equimolar amount of ethylmagnesium bromide and methylbis(trimethylsilylethynyl)fluorosilane gave the corresponding highly unsaturated mono-and binuclear first-generation dendrimers with the cores formed by the silicon atoms incorporated in silacycloalkane fragments. The 1H, 13C, and 29Si NMR spectra of all the compounds obtained were studied. The key parameters and the chemical graph of the new dendrimers are presented.

Alkylation of 2-methylimidazole with iodomethyl ketones of the aliphatic, aromatic, and heteroaromatic series

A classical procedure for the synthesis of N-alkylimidazoles is based on the reaction of imidazole with alkyl halides under pressure at 100–150°C [8]. Reactions of imidazoles with alkyl halides, α-bromo(chloro) ketones, and chloroalkyl formates in the presence of bases or phase-transfer catalysts give both N-mono[2, 3, 9] and N,N-dialkylation products [10]. Alkylation of imidazole derivatives with α-iodo ketones in the absence of a base and catalyst has not been reported so far. There are grounds to believe that α-iodo ketones can be successfully used in the synthesis of diazolyl ketones in one preparative step due to high reactivity of the C–I bond therein. For this purpose, we examined the reactions of 2-methyl-1H-imidazole (I) with 1-iodopropan-2-one (IIa), 1-(biphenyl-4-yl)-2-iodoethanone (IIb), and 2-iodo-1-(2-thienyl)ethanone (IIc) in acetone at 40°C. These reactions led to the formation of mixtures of 2-methyl-1,3-bis(2-oxopropyl)-3H-imidazol-1-ium, 1,3-bis[2-(biphenyl-4-yl)-2-oxoethyl]-2-methyl-3Himidazol-1-ium, and 2-methyl-1,3-bis-[2-oxo-2-(2thienyl)ethyl]-3H-imidazol-1-ium iodides IIIa–IIIc with the corresponding triiodides IVa–IVc. The ratio of iodides III and triiodides IV is determined by the ability of iodo ketones IIa–IIc to undergo reduction with hydrogen iodide liberated as a result of first alkylation. Triiodide ion is formed via addition of iodide ion to molecular iodine arising from the reduction of ketones IIa–IIc with hydrogen iodide.

Mononuclear polyunsaturated organosilicon dendrimers simultaneously containing (CH=CH) and (C≡C) fragments

Mononuclear organosilicon tri- and tetradendrons of the zero, first, and second generations, containing double bonds in the internal near-core molecular sphere, internal C≡C groups, and terminal Me, CH=CHSiMe3, and C≡CH substituents at the central silicon atom were synthesized. Their IR and 1H, 13C, 29Si NMR spectra were studied. The molecular weights of the dendrimers obtained were evaluated, and key parameters of these compounds are presented.

1,1-Diethynylsilacycloalkanes and Propellanes Based Thereon

Previously unknown 1,1-diethylnylsilacycloalkanes (CH2)4nSi(C& = CH)2 (n = 3, 4) were prepared by the reaction of HC& = CMgBr with 1,1-dichlorosilacycloalkanes (CH2)4nSiCl2 (n = 3, 4). The reaction of (CH2)4Si(C& = CMgBr)2 with (CH2)4SiCl2 in THF under conditions of high dilution gives cyclo(tetramethylene)- silethynes [(CH2)4SiC& = C]4 with an admixture of cyclodi(tetramethylene)silethyne [(CH2)4SiC& = C]2. The re- action of Me2Si(C& = CSiMe2C& = CMgBr)2 with (CH2)4SiCl2 was used to prepare 1,1,4,4,7,7-hexamethyl-10,10- tetramethylene-1,4,4,10-tetrasilacyclododeca-2,5,8,11-tetrayne.

Alkylation of 1,3-bis(benzotriazol-1-yl)propan-2-one with α-iodo ketones

Functionalized bis-azoles can be obtained by alkylation. However, published data on such reactions are few in number, presumably because of low reactivity of bis-azoles toward conventional alkylating agents. It is only known that the alkylation of bis(benzotriazolyl)arenes with bis(bromomethyl)arenes leads to the corresponding cyclophanes in 30–50% yield [5]. Alkylation of 1,3-bis(benzotriazol-1-yl)propan-2-one with α-iodo ketones was not described.

Synthesis of the first organylcyclosiloxane containing a benzimidazole fragment in the cycle

Cyclosiloxanes are monomers for the preparation of corrosion-resistant sealants, lubricants, hydraulic fluids, and rubbers operating over a wide temperature range [1, 2]. Main procedures for the synthesis of cyclosiloxane derivatives are based on catalytic rearrangement of polysiloxanes [3], cyclooligomerization of acetoxysilanes [4], and hydrolytic polycondensation of fluoropropylmethyl[5], polyfluorocyclobutyl[6], methylphenyl[7], and hydrogen-containing dichlorosilanes [8] with subsequent thermocatalytic treatment of the hydrolysis products. We now propose a new one-step procedure for the preparation of organylcyclosiloxane III via reaction of benzimidazole (I) with 1,3-bis(iodomethyl)-1,1,3,3tetramethyldisiloxane (II). The reaction was carried out in melt (190°C, 1 h) and is likely to involve N,N-alkylation of diazole I with disiloxane II through insertion of intermediate silanones into intermediate A molecule. In keeping with the α-elimination concept [9–11], the formation of silanone may be expected to result from coordination of the oxygen atom in siloxane II to proton of hydrogen iodide and subsequent decomposition of the complex thus formed. The structure of cyclosiloxane III was proved by elemental analyses and IR, H, C, N, and Si NMR, and mass spectra. The H and C NMR spectra of ISSN 1070-4280, Russian Journal of Organic Chemistry, 2014, Vol. 50, No. 9, pp. 1377–1379.