Chemo- and regioselective ethynylation of 4,5,6,7-tetrahydroindoles with ethyl 3-halo-2-propynoates

4,5,6,7-Tetrahydroindoles undergo a rapid, facile (rt, 60 min) ethynylation with ethyl 3-halo-2-propynoates upon grinding with solid K₂CO₃ (without solvent) at C-2 of the tetrahydroindole ring to afford ethyl 3-(4,5,6,7-tetrahydroindol-2-yl)-2-propynoates in 62–90% yield.     

Direct functionalization of the C—H bond in (hetero)arenes: aerobic photoinduced oxidative coupling of azines with aromatic nucleophiles (SNH-reactions) in the presence of a CdS/TiO2 photocatalyst

A highly selective coupling of azines with aromatic nucleophiles (S_N^H-reactions) in the presence of a heterogeneous oxidation system O₂/CdS/TiO₂ upon exposure to daylight was accomplished.     

<Superscript>13</Superscript>C-<Superscript>13</Superscript>C spin-spin coupling constants in structural studies: XL. Conformational analysis of <Emphasis Type="Italic">N</Emphasis>-vinylpyrroles

Conformational analysis of ten N-vinylpyrroles was performed on the basis of experimental ¹³C-¹H and ¹³C-¹³C coupling constants and those calculated by high-level quantum-chemical methods, and principal relations between J _CC and J _CH values and stereochemical structure of these compounds were revealed.     

Dipole moments and molecular conformations ofO-vinyl- andO-ethylacetoximes in solutions

Dipole moments of the molecules ofO-vinyl- andO-ethylacetoximes in octane and THF were measured at different temperatures. In octane, the equilibrium mixture of stableO-vinylacetoxime conformers consists of forms with different polarity. Polarity of these conformers, which are due to rotation about the C−O and N−O bonds, is mainly determined by the relative position of the lone electron pairs of nitrogen and oxygen atoms. The fraction of the polar conformer increases as temperature increases, as well as on going from octane to THF. Saturation of the vinyl group in theO-vinylacetoxime molecule nearly halves the molecular dipole moment in the nonpolar medium, which radically differentiates this compound from vinyl ethers. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1685–1690, September, 1999.     

Assembling of Complex Heterocyclic Ensembles, Schiff Bases, from 5-Amino-3-[2-(4,5,6,7-tetrahydroindolyl)]pyrazoles and 1-Vinyl(ethyl)-2-formylimidazoles

Condensation of 5-amino-3-(2-pyrrolyl)pyrazoles with 1-vinyl(ethyl)-2-formylimidazoles afforded complex heterocyclic ensembles: Schiff bases containing pyrrole, pyrazole, and imidazole rings. The cis,trans-orientation of CH = N and CH₂ = CH groups and E-isomeric structure of the Schiff bases under study with respect to the imine fragment, and also the presence of intra- and intermolecular hydrogen bonds were established.     

Synthesis ofN-allenylazoles from azoles and propargyl chloride or 1,2,3-trichloropropane in one preparative step

Reactions of imidazole and 1,2,4-triazole with propargyl chloride and its more accessible equivalent, 1,2,3-trichloropropane, in the superbasic KOH-DMSO system have been studied. The reactions afford the correspondingN-allenylazoles in one preparative step. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2005–2007, November, 1997.     

Synthesis and liquid-crystalline properties of derivatives of 5-amino-2-arylpyrimidines of the structurally stabilized anil type

We have studied the liquid crystalline properties of the synthesized alkoxy-substituted 5-salicylidenainirio-2phenylpyrirnidines compared with the corresponding benzylidene derivatives and as a function of the substituents.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 30, No. 1, pp. 93–95, January, 1994. Original article submitted December 9, 1993.     

Unexpected loss of functionality during the Trofimov synthesis of pyrroles from 4-nitro and 4-dimethylaminoacetophenone oximes

Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, p. 1963, December, 1989.