V. N. Elokhina

Synthesis and crystal structure of Cu(II) complex with 4-(pyridyl-2)-1,2,4-triazole

Abstract The synthesis and X-ray structure of new Cu(II) complex with 4-(pyridyl-2)-1,2,4-triazole (pytrz) are reported. The crystal structure of [Cu3(pytrz)8(H2O)4](NO3)6 has been determined by X-ray diffraction. Crystals are triclinic, space group P-1, unit cell parameters are: a=11.971(2), b=13.079(3), c=14.439(2) A , α=114.03(1), β=97.79(1), γ=111.02(1)°, V=1819.2(6) A 3 , Z=1, Rf=0.0706. The structure consists of linear trinuclear cations with a +6 charge and six noncoordinated NO3− anions. The central copper(II) atom is located on an inversion centre and is coordinated by six nitrogen atoms of pytrz molecules bridging via the nitrogen atoms in the N 1 , N 2 positions. Each external copper(II) atom completes its coordination sphere with one monodentate pytrz via the nitrogen atom in the N1 position and two coordinated water molecules.

Functionally substituted 1,3-diethenyl [1,2- c ][1,3]pyrrolothiazoles from pyrrole-2-carbodithioates

The reaction of pyrrole-2-carbodithioates with methylenoactive nitriles and 2-benzoyl-1-bromoacetylene in the KOH-DMSO system leads to functionally substituted pyrrolothiazoles in 59-85% yield.

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).

Thiophene-2-carbaldehyde and benzaldehyde thiosemicarbazones in reactions with propargyl bromide and 1,3-dibromopropyne

The reaction of thiophene-2-carbaldehyde and benzaldehyde thiosemicarbazones with propargylbromide in methanol provided S-(2-propyne)thiosemicarbazones hydrobromides of thiophene-2-carbaldehyde and benzaldehyde. Reaction products obtained from thiosemicarbazones and 1,3-dibromopropyne in methanol at heating were 2-thenilydene(benzylidene)azino-4-bromomethylidene-4,5-dihydrothiazol-3-ium bromides.

Synthesis and X-Ray Diffraction Study of 2-(2-Acyl-1-phenylethenyl)pyrroles

Pyrroles add to 2-acyl-1-phenylacetylenes on the surface of silicon dioxide at 20-90°C affording structurally stable Z-isomers of 2-(2-acyl-1-phenylethenyl)pyrroles containing a strong intramolecular hydrogen bond. The geometry of these molecules was established by X-ray diffraction analysis of a single crystal of 2-(2-benzoyl-1-phenylethenyl)-4,5,6,7-tetrahydroindole.

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.

Pyrroles as C-nucleophiles in reactions with acylacetylenes

The reactions of substituted pyroles with terminal acylacetylenes occur selectively to form 2-(Z/E-2-acylvinyl)pyrroles. When the reactions are performed on the surface of silica gel,C-vinylation is noticeably accelerated to form predominantlyE-isomers. ESR spectroscopy with the use of a spin trap demonstrated the ion-radical character of the process. The structures of the adducts synthesized, which exist asanti-s-cis- andsyn-s-cis-rotomers, were studied by IR, UV, and NMR spectroscopy.

Cu(II) and Co(II) complexes with 3,5-diphenyl-4-amino-1,2,4-triazole: Synthesis and study

The Cu(II) and Co(II) complexes with 3,5-diphenyl-4-amino-1,2,4-triazole (L) of the composition CuLA2 · H2O (A = Cl−, Br−), CuL2A2 (A = Cl−, Br−, NO3−), CoL2A2 · nH2O (A = Cl−, n = 1; A = NCS−, n = 0) are synthesized. In these complexes, the ligand L is coordinated to a metal in monodentate mode through the heterocyclic N(1) atom. The Cu: L = 1: 1 complexes have binuclear structures with the anions acting as bridges, whereas the M: L = 1: 2 complexes are mononuclear. Both ferro-and antiferromagnetic exchange interactions are detected for the synthesized complexes.

Synthesis of functionally-substituted pyrrolothiazolidines from pyrrole-2-carbodithioates, CH-acids, and haloacetylenes

Functionally substituted pyrrolothiazolidines have been synthesized by the sequential treatment of pyrrole-2-carbodithioates with methylene-reactive nitriles and haloacetylenes in a KOH-DMSO system.

Reactions of Pyrrole-1- and Pyrrole-2-carbodithioates with Activated Acetylenes

Pyrrole-1- and pyrrole-2-carbodithioates react with activated alkenes (KOH-DMSO, room temperature) along the nucleophilic addition mechanism regio- and stereospecifically to afford pyrrole-1-and pyrrole-2-carbodithioethenes. The adducts of pyrrole-2-carbodithioates under the reaction conditions undergo intramolecular cyclization into pyrrolothiazoles derivatives.