1-(Heteryloxy)silatranes

Novel heterocyclic 1-derivatives of silatranes have been obtained. The optimal, synthetic method for the indicated compounds is transesterification of tetraethoxysilane by an equimolar mixture of triethanolamine and a heterocyclic (or aromatic) hydroxyl-containing compound.Dedicated to the 100th anniversary of the birth of Academician A. N. Nesmeyanov.Latvian Institute of Organic Synthesis, Riga LV-1006, Latvia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1203–1206, September, 1999.     

1-organyl-3-(2-vinyloxyethoxymethyl)silatranes

Conclusions The reaction of N-[2-hydroxy-2-(2-vinyloxyethoxymethyl)ethyl]-bis(2-hydroxyethyl)amine with organyltriethoxysilanes at 20–40°C gave previously unreported 1-organyl-3-(2-vinyloxy-ethoxymethy)silatranes, (R=CH₃, ClCH₂, CH₂=CH, C₆H₅, C₂H₅O).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 740–742, March, 1989.     

Crystal and molecular structure of 1-(iodmethyl)- and 1-(iodpropyl)silatranes

The crystal and molecular structures of 1-(iodmethyl)silatrane and 1-(iodpropyl)silatrane are determined by X-ray diffraction. The effect of the iodine heteroatom upon silatrane moieties of the molecules through oneand three-carbon chains is studied based on the geometric characteristics of the molecules and the analysis of their packings.     

A new method for the preparation of 1-(chloromethyl)- and 1-(dichloromethyl)silatranes

A preparative method for the synthesis of 1-(chloromethyl)- and 1-(dichloromethyl)silatranes was developed based on the reactions of 1-chlorosilatrane with the binary P(NMe₂)₃–СHX₃ system (X₃ = HBrCl, Cl₃).

     

Basicity of silatranes (Review)

The silatranes basicity study results are summarized. A large amount of experimental data obtained 25-40 years ago is critically reviewed. It is shown that the reactivity and physicochemical properties of silatranes are determined by their basicity, which depends on the stereoelectronic structure.     

Paramagnetic Cu<Superscript>II</Superscript> complexes with 1-(hetarylmethyl)silatranes

The structures of paramagnetic complexes CuCl₂?L with L = HetCH₂Si(OCH₂CH₂)₃N [Het = pyrrol-1-yl (1), indol-1-yl (2), carbazol-9-yl (3), imidazole-1-yl (4), 3,5-dimethylpyrazol-1-yl (5), 1,2,4-triazol-1-yl (6), benzimidazol-1-yl (7), and 1,2,3-benzotriazol-1-yl (8)] were studied by the ESR and quantum chemical methods in terms of the density functional theory (DFT) approximation. The difference in structures of complexes CuCl₂?1—CuCl₂?8 is mainly determined by the nature of the five-membered heterocycle. The ESR spectra at room temperature are typical of the mononuclear complexes of Cu^II of axial symmetry with various types of distortions. In complexes CuCl₂?1—CuCl₂?3, narrow symmetric signals of zero-valent copper are recorded. These signals remain in the spectra for at least six months, which can characterize them as efficient stabilizing matrices of nanoparticles.     

Rotational isomerism of some 1-substituted silatranes

Conclusions It was shown by the DM method that the conformation of the side chain is realized in the 1--halo-propylsilatranes, the gauche form is realized predominantly in the 1-thioethoxymethylsilatranes, while a trans orientation of the C-S bond with respect to the silatrane fragment is realized in the 1--thioethoxye-thylsilatranes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7. pp. 1671–1673, July, 1977.     

Complexes of 1-(<Emphasis Type="Italic">N</Emphasis>-heterylmethyl)silatranes with metal chlorides

The hitherto unknown complexes of 1-(N-heterylmethyl)silatranes HetCH₂Si(OCH₂CH₂)₃N (Het is imidazolyl, 3,5-dimethylpyrazolyl, 1,2,4-triazolyl, benzimidazolyl, 1,2,3-benzotriazolyl) with chlorides of divalent metals MCl₂ (M = Cu, Zn, Cd, Co, Pd) of 1:1 composition are synthesized. The ligands are coordinated to the metal ion by the pyridine nitrogen atom of the azole heterocycle.     

(Z)-2-(1H-咪唑-1-基)-1-(2,3,4-三甲氧基)苯乙酮肟酯的设计与合成

三甲基苯乙酮肟;立体异构体;(Z)-2-(1H-咪唑-1-基)-1-(2;3;4-三甲氧基)苯乙酮肟酯的设计与合成     

Preparation,molecular structures,and characteristic properties of (E)-1-(2-furyl)- and (E)-1-(2-thienyl)-2-(3-guaiazulenyl)ethylenes and (E)-1-(3-furyl)- and (E)-1-(3-thienyl)-2-(3-guaiazulenyl)ethylenes

Wittig reactions of 2-furaldehyde (20) [and thiophene-2-carbaldehyde (21)] with (3-guaiazulenylmethyl)triphenylphosphonium bromide (19) in ethanol containing NaOEt at 25 °C for 24 h under argon give (E)-1-(2-furyl)-2-(3-guaiazulenyl)ethylene (22E) and (E)-1-(2-thienyl)-2-(3-guaiazulenyl)ethylene (23E) in 53 and 36% yields. Similarly, Wittig reactions of 3-furaldehyde (29) [and thiophene-3-carbaldehyde (30)] with 19 under the same reaction conditions as for 20 and 21 afford (E)-1-(3-furyl)-2-(3-guaiazulenyl)ethylene (31E) and (E)-1-(3-thienyl)-2-(3-guaiazulenyl)ethylene (32E) in 32 and 46% yields. Molecular structures and characteristic properties as well as preparation of the title E (i.e., one of the geometrical isomers) forms, with a view to comparative study, are reported. Moreover, reactions of those conjugated π-electron systems with TCNE (=tetracyanoethylene) in benzene [and in DMF (=N,N-dimethylformamide)] at 25 °C for 24 h under argon yield unique products, possessing interesting molecular structures, respectively, whose characteristic properties and crystal structures are documented, also.     

Palladium-catalyzed allylic oxidation of 1-(p-toluenesulfonyl)-2-propene and 1-(trimethylsilyl)-1-(p-toluenesulfonyl)-2-propene

The course of palladium-catalyzed oxidation of a terminal alkene by t-BuOOH or by O₂/H₂O is greatly modified when the allylic carbon bears a p-toluenesulfonyl substituent, and allylic oxidation results. Mechanistic explanations of this observation are proposed.     

4-(Arylaminothiocarbonyl)-1-(1-o-methoxyphenylcarbamido)-ethylpiperazines as anticonvulsants

Several 4-(arylaminothiocarbonyl)-1-(1-o-methoxyphenylcarbamido)-ethylpiperazines were synthesized and evaluated for their anticonvulsant activity against pentylenetetrazol-induced seizures in mice. The ability of substituted piperazines to inhibit in vitro respiratory activity of rat brain homogenates was also determined to study their structure-activity relationship.