Cyanoacetylene and Its Derivatives: XXXIV. Nucleophilic Addition of Tetrazole to Cyanoacetylenes

Nucleophilic addition of tetrazole to 4-hydroxy-4-alkyl-2-alkynonitriles and to 3-phenyl-2-propynonitrile occurred regiospecifically and afforded E-, Z-4-hydroxy-4-methyl-3-tetrazolyl-2-alkenonitriles and 3-tetrazolyl-3-phenyl-2-propenonitrile [20–40°C, 13–50 h, 4–15 wt% MOH (M = Na, K), THF (or DMSO)] in up to 69% yield. The attempt to perform cyclization of the hydroxy-containing adducts into iminodihydrofurans (KOH, ethanol, 23-25°C) resulted in vinyl nucleophilic substitution of the tetrazole moiety by an ethoxy group.     

N,N′-bis(2-Vinyloxyethyl)carbodiimide

Previously unreported N,N-bis(2-vlnyloxyethyl)carbodiimide was synthesized by the reaction of N,N -bis(2-vinyloxyethyl)thiourea with yellow mercuric oxide in CH₂Cl₂ at room temperature.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1897–1898, August, 1990.     

Conformational structure of divinyl sulfide

The potential of internal rotation about the bond for vinyl methyl sulfide is applied with some modifications to rotation about the analogous bonds in the divinyl sulfide molecule. The potential energy map of divinyl sulfide is discussed with regard to the excited torsional vibrational states. Three stable conformers with approximately identical energies were established. For a complete picture of the rotational isomerism it is also necessary to take account of the torsional vibrational stationary states with large amplitude.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1531–1535, July, 1991.     

Reactions of 1-Allenylpyrazole and 1-Allenyl-1,2,4-triazole with Hydrogen Chloride and Metal Chlorides

1-Allenylpyrazole and 1-allenyl-1,2,4-triazole react with hydrogen chloride via proton addition at the pyridine-like nitrogen atom (N² and N⁴, respectively). In the reaction with 1-allenylpyrazole, 1-[(E)-3-chloro-1-propenyl]pyrazole is also formed via regio- and stereoselective addition of hydrogen chloride to the propadienyl group. 1-Allenylpyrazole and 1-allenyl-1,2,4-triazole act as unidentate ligands with respect to Co, Ni, Cu, Zn, Cd, Pd, and Sn, the donor centers being N² and N⁴, respectively. Apart from mononuclear coordination compounds, 1-allenylpyrazole gives rise to polymeric complexes which contain units and blocks formed by the free ligand.     

Substituted dienic 1,3-dioxolan-2-ones and bis(1,3-dioxolan-2-ones)

Alkylthio-substituted dienic 1,3-dioxolan-2-ones and bis(4,4-diorganyl-5-methyli-dene-1,3-dioxolan-2-ones) were obtained in high yields by the reaction of 2-methyl-6-alkylthio-5-hexen-3-yn-2-ols and tertiary diacetylenic glycols with carbon dioxide under pressure in the presence of catalytic amounts of triethylamine and monovalent copper salts.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1617–1619, December, 1979.Original article submitted January 24, 1979.     

Pyrroles from ketoximes and acetylene

The ¹³C NMR spectra of eight 2-alkyl- and 2,3-dialkyl-1-vinylpyrroles were studied. The ¹³C chemical shifts of all of the carbon atoms of the ring and the vinyl group depend substantially on the position and structure of the alkyl substituent. As the branched character of the alkyl group in the 2 position increases, the signal of the -carbon atom of the vinyl group is shifted to weak field due to weakening of the p- conjugation in the N-vinyl group because of disruption of its coplanarity with the pyrrole ring. The conjugation between the double bond and the pyrrole system involves competition for possession of the p electrons of the nitrogen atom.See [16] for communication II.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 350–354, March, 1978.     

Trialkyl-n-(2-vinyloxyethyl)ammonium salts — New systems akin to acetylcholine

Conclusions Vinyloxyethyltrialkylammonium salts possessing strong hypertensive activity were prepared by reacting 2-(dialkylamino)ethyl vinyl ethers with alkyl iodides and 2-halogenoethyl vinyl ethers with tertiary amines.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1178–1180, May, 1969.     

Study of the Structure and Reactions of Bis(μ-Oxalato)tetramminediplatinum(II) in Aqueous Chloride Solutions

A comparison study of the bis(-oxalato)tetramminediplatinum(II) dimer [Pt₂(NH₃)₄(-C₂O₄)₂] and the oxalatodiammineplatinum(II) chelate [Pt(NH₃)₂C₂O₄] is performed. The kinetics and mechanism of substitution of C₂O^2– ₄ for Cl^– in aqueous chloride solutions are studied by photoelectronic spectroscopy, gravimetry, and chemical phase analysis within the 1.0–6.7 pH range at 75°C. The rate constants of substitution and the equilibrium constants for a two-step protonation for the dimeric and chelate complexes are calculated. Their solubility in 1 M KCl at 75°C; is determined. The unit cell parameters for [Pt₂(NH₃)₄(-C₂O₄)₂] are determined: a = 3.858 Å, b = 10.704 Å, c = 6.795 Å, = 94.35°. The IR spectra of [Pt(NH₃)₂C₂O₄], [Pt₂(NH₃)₄(-C₂O₄)₂], and their deuterated analogs are studied.     

N-isopropenylazoles: III. Quantum-chemical analysis of the reaction of azoles with allene and propyne in the gas phase

Reactions of pyrrole, imidazole, pyrazole, and 1,2,4-triazole with allene and propyne in the gas phase with formation of the corresponding N-isopropenylazoles were simulated at the RHF/6-31G**, B3LYP/6-31G**, and MP2(full)/6-31G** levels. Dissociation of the N-H bond to give azolate ion is the main constituent of the reaction coordinate. All the examined azoles react preferentially with allene rather than with propyne; their reactivity decreases in the series pyrrole > imidazole > pyrazole > 1,2,4-triazole due to participation of the pyridine type nitrogen atoms in the prototropic propyne-allene rearrangement.     

Stereochemical memory versus Curtin-Hammett behavior in the rearrangement of 1,3-cyclopentanediyl radical cations derived from housanes through structural effects on conformational control

The electron-transfer-catalyzed rearrangement of the housanes 1 affords regioselectively the two cyclopentenes 2 and 3 by 1,2-migration of a group at the methano bridge. Appropriate ring annelation in the intermediary cyclopentane-1,3-diyl radical cation 1(*+) changes the stereochemical course of the rearrangement from complete stereoselectivity (stereochemical memory) for the structurally simple housane 1b to partial loss of stereoselectivity through competing conformational interconversion for the tricyclic housane 1c. Additional cyclohexane annelation, as in the tetracyclic housane 1a, results in complete loss of stereocontrol through Curtin-Hammett behavior, as substantiated by the viscosity dependence on the product ratio of the rearrangement. Whereas in the radical cations 1b(*+) and 1c(*+) the 1,2-shifts (k(2) and k(3)) are faster than the conformational anti <==> syn change (k(1), k(-1)), the reverse applies for the radical cation 1a(*+). Such structural manipulation of conformational effects in radical cation rearrangements has hitherto not been documented.