6,6′-Bis(1,5-diazabicyclo[3.1.0]hexane)

The interaction of 1,3-diaminopropane with glyoxal and NaOCl in water at pH 9.5–10.5 afforded the previously unknown 6,6′-bis(1,5-diazabicyclo[3.1.0]hexane). According to X-ray diffraction data, both bicyclic fragments of the title compound adopt a boat conformation. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 623–625, March, 1999.     

Assembling of 3,6-diazabicyclo[3.1.0]hexane framework in oxidative triflamidation of substituted buta-1,3-dienes

Reaction of trifluoromethanesulfonamide (triflamide) CF₃SO₂NH₂ with 2,3-dimethylbuta-1,3-diene (2) and 2,5-dimethylhexa-2,4-diene (3) in the oxidative system (t-BuOCl+NaI) results in the formation of 2,4-dimethyl- or 2,2,4,4-tetramethyl-3,6-bis(triflyl)diazabicyclo[3.1.0]hexane through two successive heterocyclizations. Reaction of diene (3) with arenesulfonamides ArSO₂NH₂ (Ar=Ph, Tol), stops at the formation of the product of oxidative 1,4-addition, N,N′-(2,3-dimethylbut-2-ene-1,4-diyl)diarenesulfonamides, providing evidence of the essential difference between the reactivity of triflamide and arenesulfonamides.     

First synthesis of 1,5-diazabicyclo[3.1.0]hexane complexes with cadmium salts

Complexes of bicyclic diaziridines 6,6′-bi(1,5-diazabicyclo[3.1.0]hexane) (L ¹ ) and 6-(4-methoxyphenyl)-1,5-diazabicyclo[3.1.0]hexane (L ² ) with the salts Cd(NO₃)₂ · 4H₂O and Cd(ClO₄)₂ · 6H₂O have been synthesized. The fact of complexation has been established by cyclic voltammetry. The crystal structure of complex L ¹ with Cd(NO₃)₂ (the coordination number of cadmium is 8) has been studied by X-ray diffraction.     

Electron Diffraction Study of the Molecular Structure of 6,6'-Bis(1,5-diazabicyclo[3.1.0]hexane)

Gas-phase electron diffraction using quantum-chemical calculations was employed to study the molecular structure for 6,6'-bis(1,5-diazabicyclo[3.1.0]hexane). The conformation of the bicyclic fragment is boat or anti relative to the exocyclic bond.     

Molecular structure of 1,5-diazabicyclo[3.1.0]hexane as determined by gas electron diffraction and quantum-chemical calculations

The equilibrium molecular structure and conformation of 1,5-diazabicyclo[3.1.0]hexane (DABH) has been studied by the gas-phase electron-diffraction method at 20 degrees C and quantum-chemical calculations. Three possible conformations of DABH were considered: boat, chair, and twist. According to the experimental and theoretical results, DABH exists exclusively as a boat conformation of C s symmetry at the temperature of the experiment. The MP2 calculations predict the stable chair and twist conformations to be 3.8 and 49.5 kcal mol(-1) above the boat form, respectively. The most important semi-experimental geometrical parameters of DABH (r(e), A and angle)e), deg) are (N1-N5) = 1.506(13), (N1-C6) = 1.442(2), (N1-C2) = 1.469(4), (C2-C3) = 1.524(7), (C6-N1-C2) = 114.8(8), (N5-N1-C2) = 107.7(4), (N1-C2-C3) = 106.5(9), and (C2-C3-C4) = 104.0(10). The natural bond orbital (NBO) analysis has shown that the most important stabilization factor in the boat conformation is the n(N) --> sigma*(C-C) anomeric effect. The geometry calculations and NBO analysis have been performed also for the bicyclohexane molecule.     

Synthesis of unsubstituted 1,3,5-triazabicyclo[3.1.0]hexane

Unsubstituted 1,3,5-triazabicyclo[3.1.0]hexane has been syntesized for the first time by treating a Henry solution with NaOCl.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1665–1666, September, 1993.     

Synthesis of 1-azabicyclo[3.1.0]hexane systems

The synthesis of aziridino[1,2-a]pyrrolidine systems related to the azinomycin family of antitumor agents is reported and was based on an intramolecular addition-elimination reaction sequence. Department of Chemistry, Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, USA. Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1632–1635, December, 1998.     

Regioselectivity in the Addition of 1,3-Dipolarophiles to 6-Aryl-1,5-diazabicyclo[3.1.0]hexanes

Thermolysis of 6-aryl-1,5-diazabicyclo[3.1.0]hexanes in the presence of 1,3-dipolarophiles having an unsymmetrically substituted double C=C bond (such as N-arylimides derived from 2-aryl-substituted maleic, citraconic, and itaconic acids, ethyl propynoate, aryl isocyanates, and aryl isothiocyanates) leads to formation of the corresponding 1,3-dipolar cycloaddition products. The reaction is regioselective, and in most cases only one regioisomer is obtained. The addition direction depends on the 1,3-dipolarophile structure, i.e., electronic and steric factors determining the most effective orbital interaction upon approach of the reagent to substrate.     

Stereoselectivity in the Addition of 1,3-Dipolarophiles to 6-Aryl-1,5-diazabicyclo[3.1.0]hexanes

Thermolysis of 6-aryl-1,5-diazabicyclo[3.1.0]hexanes in the presence of N-arylmaleimides having a substituent in the ortho position of the aromatic ring leads to predominant formation of the corresponding trans-9-arylperhydropyrazolo[1,2-a]pyrrolo[3,4-c]pyrazole-1,3-diones. 6-Aryl-1,5-diazabicyclo[3.1.0]hexanes react with fumaric acid derivatives in a stereoselective fashion, affording perhydropyrazolo[1,2-a]pyrazoles with a trans,trans configuration.     

Molecular structure of 6-cyclopropyl-1,5-diazabicyclo[3.1.0]hexane: gas phase electron diffraction and theoretical study

The molecular structure and conformational composition of 6-cyclopropyl-1,5-diazabicyclo[3.1.0]hexane were determined by gas phase electron diffraction and quantum chemical calculations. The gas phase electron diffraction data were well reproduced for the mixture of two conformers with anti-boat and gauche-boat mutual ring orientation having 15 and 85% relative abundance, respectively. The standard enthalpy of formation of substance under study was calculated using atomization reactions, yielding value of 307.9 ± 3.3 kJ mol^-1 in gas phase.     

NMR structural elucidation and photochromic behavior of new 1,3-diazabicyclo[3.1.0]hex-3-ene derivatives

Several 6-(4-nitrophenyl)-4-phenyl-1,3-diazabicyclo[3.1.0]hex-3-ene derivatives having various substituents on C² were synthesized, and their ¹H NMR spectra and photochromic behavior were examined.     

Copper-catalyzed cascade approach to 1,3-diazabicyclo[3.1.0]hex-3-enes from aziridines and ethyl diazoacetate

An efficient and general synthesis of 1,3-diazabicyclo[3.1.0]hex-3-enes via the copper-catalyzed cascade reaction of aziridines with ethyl diazoacetate is described.     

PMR spectra of 1,3-diazabicyclo[3.1.0]hexanes in the presence of tris(dipivaloylmethanato) europium

The PMR spectra of 1,3-diazabicyclo[3.1.0]hexanes in the presence of tris(dipivaloylmethanato)europium were studied.     

Kinetics and mechanism of the anodic dissolution of gold in solutions of 1,5-diazabicyclo[3.1.0]hexane and its precursors

Studies of the electrochemical behavior of hexahydropyrimidine, 1,5-diazabicyclo[3.1.0]hexane, and 1,3-diaminopropane on a gold electrode via cyclic voltammetry allow us to conclude that gold anodes are subject to corrosion in presence these compounds, yielding complexes that migrate into the solutions and discharge on the counter electrode, producing gold metal deposit. 1,5-Diazabicyclo[3.1.0]hexane is found to form complexes with gold that are much more stable that those formed by hexahydropyrimidine and 1,3-diaminopropane.     

Stereochemical assignments of the 6-phenyl-2-oxabicyclo[3.1.0]hexanes

Preparation and stereochemical assignments of the 6-phenyl-2-oxabicyclo[3.1.0]hexanes are reported. The stereochemical assignments are based on chemical as well as nmr data.     

Thermal decomposition products of methyl 1,5-diphenyl- and 5-methyl-1-phenyl-2,3-diazabicyclo[3.1.0]hex-2-ene-6-exo-carboxylates

Methyl 1,5-diphenyl- and 5-methyl-1-phenyl-2,3-diazabicyclo[3.1.0]hex-2-ene-6-exo-carboxylates at 138°C undergo decomposition via elimination of nitrogen molecule with formation in each case of five products. Two products are methyl 1,3-diphenyl(or 1-methyl-3-phenyl)bicyclo[1.1.0]butane-2-endo- and -exo-carboxylates, and the three others are derivatives of buta-1,3-diene, methyl (Z)-2-benzylidene-3-phenyl(or 3-methyl)but-3-enoate and methyl (E)- and (Z)-3,4-diphenyl(or 4-methyl-3-phenyl)penta-2,4-dienoates. The formation of these products may be rationalized assuming intermediacy of substituted allylcarbene which undergoes both intramolecular cycloaddition and rearrangements involving 1,2-hydride and 1,2-vinyl shifts.