The reaction of β-lactam carbenes with 3,6-dipyridyltetrazines: switch of reaction pathways by 2-pyridyl and 4-pyridyl substituents of tetrazines

The reactions of β-lactam carbenes with both 3,6-di(2-pyridyl)tetrazine and 3,6-di(4-pyridyl)tetrazine were studied. It was found that β-lactam carbenes reacted with 3,6-di(2-pyridyl)tetrazine to produce 5-triazolo[1,5-a]pyridylpyrrol-2-ones in good yields, while with 3,6-di(4-pyridyl)tetrazine, they afforded pyrido[c]cyclopenta[b]pyrrol-2-ones in moderate yields. Both reactions were proposed to follow cascade mechanisms containing a 3,6a-dipyridylpyrrolo[3,2-c]pyrazol-5-one intermediate. The different pathways of the transformation of pyrrolo[3,2-c]pyrazol-5-ones were switched by the 2- and 4-pyridyl substituents. This work not only provided a simple and efficient strategy for the construction of novel triazolo[1,5-a]pyridine and pyrido[c]cyclopenta[b]pyrrole derivatives, respectively, but also revealed two different thermal transformation patterns of 3H-pyrazole compounds.     

Regioselectivity of cyclization of 3-allyl(propargyl)sulfanyl-5<Emphasis Type="Italic">H</Emphasis>-[1,2,4]triazino[5,6-<Emphasis Type="Italic">b</Emphasis>]indoles

The interaction of 3-allylsulfanyl-5H-[1,2,4]triazino[5,6-b]indole with iodine led to 1-iodomethyl-1,2-dihydro[1,3]thiazolo[2',3':3,4][1,2,4]triazino[5,6-b]indol-11-ium pentaiodide with an angular structure, on the basis of which 1-iodomethyl-1,2-dihydro[1,3]thiazolo-, 1-methylidene-1,2-di-hydro[1,3]thiazolo, and 1-methyl[1,3]thiazolo derivatives were obtained. The intramolecular cyclization of 3-propargyl(allyl)sulfanyl-5H-[1,2,4]triazino[5,6-b]indoles under the influence of concentrated sulfuric acid led to linear annelated products:3-methyl[1,3]thiazolo[3',2':2,3][1,2,4]tri-azino[5,6-b]indole or its 2,3-dihydro derivative.     

Imidazo[1,2-α]pyridine anthelmintics. Synthesis of 6-phenylaminoimidazo[1,2-α]pyridine-2-carbamate and 5-acylaminopyridines by a chapman rearrangement

The title compound, a potential anthelmintic agent, was prepared in seven steps from 5-hydroxy-2-picoline. The intermediate 5-(N,-phenylbenzamido)-2-picoline was prepared by a facile Chapman rearrangement of the corresponding benzimidoyl ester. Oxidation and Curtius rearrangement of the substituted picoline gave 5-(N-phenylbenzamido)-2-aminopyridine which underwent ring closure and debenzoylation to furnish methyl 6-phenylaminoimidazo[1,2-α]pyridine-2-carbamate. Fries rearrangement of the penultimate N-benzoyl derivative gave a 6-(p-benzoylphenylamino)imidazo[1,2-α]pyridine derivative, whose structure was confirmed by cmr study. The title compound lacked significant anthelmintic activity.     

Synthesis of condensed structures from 3-cyano-2-pyridylacrylic acids

Ammonolysis of the methyl esters of trans--(3-cyano-2-pyridyl)acrylic (I) and trans--(6-methyl-3-cyano-2-pyridyl)acrylic (II) acids gave the amides of these acids. The addition of bromine, diazomethane, and hydrogen to the double bond of cis- and trans-acids I and II is described. Hydrogenation of the methyl esters of trans-acids I and II over Raneynickel at room temperature and atmospheric pressure occurs with intramolecular cyclization to two-ring lactams — 7-oxo-5, 6,8,9-tetrahydropyrid[3,2-c]azepine and 2-methyl-7-oxo-5,6,8,9-tetrahydropyrid[3,2-c]azepine. Under the conditons of acid hydrolysis of acids I and II the elements of water add to the nitrile group with intramolecular cyclization to give, respectively, 3-carboxymethyl-1-oxo-2,3-dihydrofuro [4,3-b]pyridine and 5-methyl-3-carboxymethyl-1-oxo-2,3-dihydrofuro[4,3-b]pyridine, whereas refluxing these acids with aqueous sodium hydroxide gives two-ring lactams — 3-carboxymethyl-1-oxo-2, 3-dihydropyrrolo[4,3-b]pyridine and its 5-methyl homolog. The structures of the compounds were confirmed by the UV, IR, PMR, and mass spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 63–69, January, 1978.     

Synthesis of novel purinyl-1'-homocarbanucleosides based on a cyclopenta[b]pyrazine system

cis-2,3-Diphenyl-6,7-dihydro-5H-cyclopenta[b]pyrazine-5,7-dimethanol, prepared by Diels-Alder reaction from cyclopentadiene and appropriately protected 2-imidazolone--followed by dihydroxylation, glycol protection, diamine deprotection, condensation with benzyl, glycol deprotection, oxidative cleavage and reduction--, was used to synthesize (+/-)-cis-([7-(6-chloro-9H-purin-9-yl)methyl]-2,3-diphenyl-6,7-dihydro-5H-cyclopenta[b]pyrazin-5-yl)methanol, a key intermediate for novel 1'-homocarbanucleosides based on a cyclopenta[b]pyrazine scaffold as shown by its conversion into several 6-substituted purinyl derivatives.     

Synthesis of Some [1,3]Benzodioxoles via the Reaction of o-Quinones with Phosphorus Ylides

3,5-Di(tert-butyl)benzo-1,2-quinone 1c, phenanthrene-9,10-quinone 11, and 1,2-naphthoquinone 18 react with 1-phenylethylidene(tri-phenyl)phosphorane 2j, cyclopentylidene(triphenyl)phosphorane 2k, cyclohexylidene(triphenyl)phosphorane 2l, and tetrahydro-2-furanyl-methylidene(triphenyl)phosphorane 8 to give the corresponding 2-substituted [1,3]benzodioxoles 5–7, 10, 12–14, 20–22 in low to high yields, instead of Wittig products, with exception of 11,12-dihydro-10H-cyclopenta[b]phenanthro[9,10-d]furan 17. A possible explanation for these reaction sequences is discussed.

     

Synthesis of 4H-1,3,4-oxadiazino[5,6-b]quinoxalines from 2-substituted quinoxaline 4-oxides

The reaction of 6-chloro-2-(1-methylhydrazino)quinoxaline 4-oxide 8 with acetic anhydride resulted in the intramolecular cyclization to give 8-chloro-2,4-dimethyl-4H-1,3,4-oxadiazino[5,6-b]quinoxaline 7a , while the reaction of compound 8 with acetic anhydride/pyridine or acetic anhydride/acetic acid afforded 3-(2,2-diacetyl-1-memymydrazmo)-7-chloro-2-oxo-1,2-dihydroquinoxaline 9 , effecting no intramolecular cyclization. The reaction of 2-(2-acetyl-1-methylhydrazino)-6-chloroquinoxaline 4-oxide 10a or 6-chloro-2-(1-methyl-2-trifluoroacetylhydrazino)quinoxaline 4-oxide 10b with phosphoryl chloride provided compound 7a or 8-chloro-4-memyl-2-trifluoromethyl-4H-1,3,4-oxadiazino[5,6-b]quinoxaline 7b , respectively. The reaction of compound 7b with phosphorus pentasulfide gave 7-chloro-3-(1-methyl-2-trifluoroacetylhydrazino)-2-thioxo-1,2-dihydroquinoxaline 11 , whose dehydration with sulfuric acid in acetic acid afforded 8-chloro-4-methyl-2-trifluoromemyl-4H-1,3,4-thiadiazino[5,6-b]quinoxaline 12 .     

Synthesis of tetra- and pentaaza heterocyclic systems and benzimidazo[1,2-c]quinazoline derivatives

5,6-Dihydropyrimido[5′,4′: 5,6]pyrido[1,2-a]benzimidazole and pyrimido[4′,5′: 4,5]pyrimido[1,6-a]-benzimidazole derivatives were synthesized starting from 3-[4-hydroxy-6-methyl(hydroxy)-2-phenylpyrimidin-5-yl]propanoic and 4-hydroxy-2-phenylpyrimidine-5-carboxylic acids. New 6-sulfanyl-substituted benzimidazo-[1,2-c]quinazolines were also prepared.     

4,5-Dihydropyrazolo[3,4-f]quinazolines

By reaction of 6-dimethylamino-5-oxo-2-phenyl-5,6,7,8-tetrahydroquinazoline with hydrazine, phenylhydrazine, 4-bromo-, 4-chlorophenylhydrazines, and also reaction of 6-dimethylaminomethylene-5-oxo-2-(4-pyridyl)-5,6,7,8-tetrahydroquinazoline with hydrazine, 4-methoxy- and 2-carboxyphenylhydrazines, we have obtained the corresponding 7-phenyl(4-pyridyl)-substituted 1H(2H)- or 1-aryl-4,5-dihydropyrazolo[3,4-f]quinazolines. Methylation of 7-phenyl-4,5-dihydro-1(2H)-pyrazolo[3,4-f]quinazoline by methyl iodide led to its 2-methyl derivative.     

Studies on tertiary amine oxides. LXVII . Reactions of aromatic N-oxides with 3-arylrhodanines in the presence of acetic anhydride

Quinoline 1-oxides 1 readily react with 3-arylrhodanines 2 in the presence of acetic anhydride to afford 3-aryl-5-(2-quinolyl)rhodanines 3 in high yields. These products resist hydrolysis under both alkaline and acidic conditions, but is oxidized to quinaldinic acid 1-oxide 4 with 30% hydrogen peroxide in hot acetic acid. Besides isoquinoline 2-oxide 5 , pyridine 1-oxide 7a also reacts in the same way to give 3-aryl-5-(2-pyridyl)rhodanines 8 , although the reactivity of γ-picoline 1-oxide 7b is considerably lower. Contrary to 3 , 3-phenyl-5-(2-pyridyl)rhodanine 8a is successfully hydrolyzed with boiling 48% hydrobromic acid to 2-pyridinemethanethiol 10 in 57% yield.     

Acid-Catalyzed Rearrangements of 5,6-exo-Epoxy-7-oxabicyclo[2.2.1]hept-2-yl Derivatives. Migratory Aptitudes of Acyl vs. Alkyl Groups in Wagner-Meerwein Transpositions

In the presence of HSO₃F/Ac₂O in CH₂CL₂, 2-exo- and 2-endo-cyano-5,6-exo-epoxy-7-oxabicyclo[2.2.1]hept-2-yl acetates ( 6a , b ) gave products derived from the epoxide-ring opening and a 1,2-shift of the unsubstituted alkyl group (σ bond C(3)–C(4)). In contrast, under similar conditions, the 5,6-exo-epoxy-7-oxabicyclo[2.2.1]heptan-2-one ( 6c ) gave 5-oxo-2-oxabicyclo[2.2.1]heptane-3,7-diyl diacetates 20 and 21 arising from the 1,2-shift of the acyl group. Acid treatment of 5,6-exo-epoxy-2,2-dimethoxy-7-oxabicyclo[2.2.1]heptane ( 6d ) and of 5,6-exo-epoxy-2,2-bis(benzyloxy)-7-oxabicyclo[2.2.1]heptane ( 6e ) gave minor products arising from epoxide-ring opening and the 1,2-shift of σ bond C(3)–C(4) and major products ( 25 , 29 ) arising from the 1,3-shift of a methoxy and benzyloxy group, respectively. Under similar conditions, 5,6-exo-epoxy-2,2-ethylenedioxy-7-oxabicyclo[2.2.1]heptane ( 6f ) gave 1,1-(ethylenedioxy)-2-(2-furyl)ethyl acetate ( 32 , major) and a minor product 33 , arising from the 1,2-shift of σ bond C(3)–C(4). The following order of migratory aptitudes for 1,2-shifts toward electron-deficient centers has been established: acyl > alkyl > alkyl α-substituted with inductive electron-withdrawing groups. This order is valid for competitive Wagner-Meerwein rearrangements involving equilibria between carbocation intermediates with similar exothermicities.     

Synthesis and reactions of ethyl 3-acetyl-8-cyano-6,7-dimethylpyrrolo[1,2-a]pyrimidine-4-carboxylate and related compounds

The reactions of 3-acetyl-4-ethoxycarbonyl- or 3,4-diethoxycarbonylpyrrolo[1,2-a]pyrimidine derivatives 7a,b , which were prepared by condensation of the 2-aminopyrrole ( 4 ) with ethyl 3-ethoxymethylene-2,4-dioxovalerate ( 5a ) or ethyl ethoxymethyleneoxaloacetate ( 5b ), with diazomethane are described. Thus, reaction of 7a , with diazomethane gave ethyl 2a-acetyl-7-cyano-2a,3a-dihydro-5,6-dimethyl-3H -cyclopropa[e]pyrrolo[1,2-a]pyrimidine-3a-carboxylate ( 11 ) in 74% yield, which was readily transformed into the 1-pyrrol-2-yl-pyrrole ( 18 ) by treatment with potassium hydroxide. On the other hand, reaction of 7b with diazomethane afforded three products whose structures were assigned as diethyl 7-cyano-2a,3a-dihydro-5,6-dimethyl-3H-cyclopropa[e]pyrrolo[1,2-a]pyrimidine-2a,3a-carboxylate ( 20 ), 6-cyano-7,8-dimethyl-3a,3b,5,9a-tetrahydro-4H -aziridino[c]-1H or 3H-pyrazolo[3,4-e]pyrrolo[1,2-a]pyrimidine-3a,9a-dicarboxylates ( 21,22 ). Ring Transformation of 20 to 25 was not observed.     

1,2,4-Triazoles—XXXIII: Photodimerization of some sym-di(3-s-triazolo-[4,3-a]pyridyl)-alkanes and related derivatives

Irradiation of 3,3'-[ethane-1,2-diyl]bis-[1,2,4-triazolo-[4,3-a]pyridine] at 300 nm gave the cisoid-fused cyclobutane dimer 5aα,5bα-10bα,10cα-tetrahydro-1,10-ethano-2,3,8,9,10a,10d-hexaazadicyclopenta[a,i]biphenylene. Under the same conditions 3,3'-[propane-1,3-diyl]bis-[1,2,4-triazolo[4,3-a]pyridine] gave the corresponding cyclobutane dimer, 5aα,5bα,10bα,10cα-tetrahydro-1,10-propano-2,3,8,9,10a,10d-hexaazadicyclopenta[a,i]biphenylene whereas at 254 nm the photoproduct obtained had the “cage-like” structure 3b,3c,3d,3e,6b,6c,6d,6e-octahydro-3, 4-propano-1,2,3a,3f,5,6-hexaazadicyclobuta[def,jkl]dicyclopenta[b,h]biphenylene. Replacement of the hydrocarbon linkage with the oxybis(methylene) or a thiobis(methylene) unit and irradiation at 300 nm gave the corresponding cisoid-fused, cyclobutane dimers only. The effect of methyl substituents in the pyridine ring of the bicyclic system on the dimerization process was also studied.     

Tetra-2,3-pyrazinoporphyrazines with externally appended pyridine rings. 1. Tetrakis-2,3-[5,6-di(2-pyridyl)pyrazino]porphyrazine: a new macrocycle with remarkable electron-deficient properties

A new pyrazinoporphyrazine macrocycle carrying externally appended pyridine rings, tetrakis-2,3-[5,6-di(2-pyridyl)pyrazino]porphyrazine (hydrated), [Py(8)TPyzPzH(2)].2H(2)O, was prepared in high yield by direct cyclotetramerization of the precursor, 2,3-dicyano-5,6-di(2-pyridyl)-1,4-pyrazine, [(CN)(2)Py(2)Pyz], in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). The single-crystal X-ray structure of [(CN)(2)Py(2)Pyz] shows a noncoplanar positioning of the pyrazine and pyridine rings in the two slightly different independent molecular units present in the crystal. UV-vis spectra of [Py(8)TPyzPzH(2)] were measured in two nondonor solvents (CHCl(3), CH(2)Cl(2)), a slightly basic solvent (pyridine), and an acidic solvent (CH(3)COOH). In all cases, the spectral changes are consistent with the occurrence of molecular aggregation and colloidal dispersions which break up with time to give clear solutions containing exclusively the monomeric form of the macrocycle, either neutral [Py(8)TPyzPzH(2)] (in CHCl(3), CH(2)Cl(2), and CH(3)COOH) or dianionic [Py(8)TPyzPz](2)(-) (in pyridine). A spectrally monitored titration of [Py(8)TPyzPzH(2)] in CH(2)Cl(2) with TBA(OH) shows the loss of two protons from the macrocyclic core and quantitative conversion of [Py(8)TPyzPzH(2)] to [Py(8)TPyzPz](2)(-). Cyclic voltammetry and thin-layer spectroelectrochemical measurements show that [Py(8)TPyzPzH(2)] is present in CH(2)Cl(2) while [Py(8)TPyzPz](2)(-) is present in pyridine, but both forms of the compound exhibit identical electrochemical behavior, consistent with a conversion of the dianion to the neutral porphyrazine in pyridine prior to electroreduction via four reversible one-electron transfer steps. No oxidations of the macrocycle are observed in either solvent containing 0.1 M tetrabuthylammonium perchlorate (TBAP). A comparison of the electrochemical behavior for [Py(8)TPyzPzH(2)] with what is reported for related phthalocyanine and porphyrazine analogues highlights the remarkable electron-accepting properties of the presently investigated free-base macrocycle.     

Synthesis of novel 2-azabicyclo[2.2.0]- and [2.1.1]hexanols

Methyl- and phenyl-substituted N-(ethoxycarbonyl)-2-azabicyclo[2.2.0]hex-5-enes 6 were reacted with NBS in wet DMSO to afford bromohydrins. Mixtures of unrearranged 6-exo-bromo-5-endo-hydroxy-2-azabicyclo[2.2.0]hexanes 7a,b and rearranged 5-anti-bromo-6-anti-hydroxy-2-azabicyclo[2.1.1]hexanes 8a,b were formed stereoselectively from the parent alkene 6a and 4-methyl alkene 6b. The 5-methyl alkene 6c affords only unrearranged bromohydrin 7c and dibromohydrin 9. By contrast, solely rearranged 3-endo-substituted-2-azabicyclo[2.1.1]hexane bromohydrins 8d-f result from additions to 3-endo-methyl alkene 6d, 3-endo-4-dimethyl alkene 6e, and 3-endo-phenyl alkene 6f. As an alternative route to bromohydrins, the parent 5,6-exo-epoxide 10a and 5-endo-methyl-5,6-exo-epoxide 10b were ring opened with bromine/triphenylphosphine to afford unrearranged 5-endo-bromo-6-exo-hydroxy-2-azabicyclo[2.2.0]hexanes 11a,b, while the 3-endo-methyl epoxide 10c afforded solely the rearranged 5-anti-bromo-6-anti-hydroxy-3-exo-methyl-2-azabicyclo[2.1.1]hexane isomer 8g. Tributyltin hydride reduction of bromohydrins 7a,b and 11a afforded novel 2-azabicyclo[2.2.0]hexan-5-ols 13a,b and -6-ol 14, and bromohydrins 8a,b, 8d-g afforded new 2-azabicyclo[2.1.1]-hexan-5-ols 15a,b and 15d-g.     

The reaction of 2-acetoacetamidopyridines with phosgene. A route to novel 3-Acetyl-2-chloro-4H-pyrido[ 1,2-a] pyrimidin-4-ones

2-(Acetoacetamido)pyridine, 1 , and its 5-methyl derivative, 2 , with phosgene, gave 3-acetyl-2-chloro-4H-pyrido[1,2-a]pyrimidin- 4 -one, 5 , and 3-acetyl-2-chloro-7-methyl-4H-pyrido[1,2-a]-pyrimidin-4-one, 6 , respectively. The structures of these compounds followed from their elemental analyses, and interpretations of their uv, ir, pmr, and X-ray spectra. An alternative route to 5 and 6 , which sought first to react 1 and 2 with methyl - and benzyl chloroformates, was unsuccessful, and led, instead, to elimination of the acetoacetyl group with concomitant formation of the carbamate derivatives, 10 and 11 .     

Chemistry of Ruthenium Polypyridine Complexes: VIII. Electronic Structure and Reactivity of cis-[Ru(2,2'-Bpy)2(L)Cl]+ Complexes in Excited States

Ab initio and semiempirical CINDO/CI calculations of free ligands L and complexes cis-[Ru(bpy)₂(L)Cl]⁺ [bpy = 2,2'-bipyridyl, L = pyridine, 3-cyanopyridine, 4-picoline, nicotinamide, isonicotinamide, 4-picoline, 4-aminopyridine, 4,4'-bipyridyl (bipy), trans-1,2-bis(4-pyridyl)ethene, 4,4'-azopyridine, pyrazine (pyz), and imidazole] were used to study the interrelation between the electronic structures of the ligands and the complexes in the ground and electronically excited states and to interpret the electronic absorption spectra of the complexes. The quantum yields for photosubstitution of a solvent molecule for a ligand L were measured; for L = pyz and bipy, photolysis quantum yields as a function of irradiation wave-length were studied. The possibility of population of ligand-field photoactive states from overlying charge-transfer states and the associative mechanism of ligand photosubstitution were discussed.     

新型哌嗪化合物的合成及其晶体结构

以2-［1,2-二(2-羟基苯甲氨基)-2-(吡啶基)乙基］苯酚和2-［1,2-二(2-羟基苯甲氨基)-4-(吡啶基)乙基］苯酚为原料,分别与乙二醛经缩合反应,合成了两个新型的哌嗪化合物--2-【{12-(2-吡啶基)-3,20-二氧-11,21-二氮杂五环［11.7.1.O^2,11.O^4,9.O^14,19］二十一-4,6,8,14,16,18-六环-21-基}甲基】苯酚(2a)和2-【{12-(4-吡啶基)-3,20-二氧-11,21-二氮杂五环［11.7.1.O^2,11.O^4,9.O^14,19］二十一-4,6,8,14,16,18-六环-21-基}甲基】苯酚(2b),其结构经¹H NMR, ¹³C NMR, FT-IR, ESI-MS和X-射线单晶衍射表征。2a(CCDC: 1 439 422)属单斜晶系,空间群P2₁/n,晶胞参数a=12.250 2(16) , b=10.299 6(13) , c=18.296(2) , β=95.798(2)°, V=2 296.6(5) ³, Dc=1.341 mg·cm^-3,Z=4, F(000)=976, μ=0.088 mm^-1。     

Helix-sense-selective copolymerization of phenyl[bis(2-pyridyl)]methyl methacrylate,diphenyl(2-pyridyl)methyl methacrylate and triphenylmethyl methacrylate with chiral anionic initiators

Optically active poly[triphenylmethyl methacrylate-co-phenyl[bis(2-pyridyl)]methyl methacrylate] (poly[TrMA-co-PB2PyMA], poly[diphenyl(2-pyridyl)methyl methacrylate-co-phenyl[bis(2-pyridyl)]methyl methacrylate] (poly[D2PyMA-co-PB2PyMA]), and poly[triphenylmethyl methacrylate-co-diphenyl(2-pyridyl)-methyl methacrylate] (poly[TrMA-co-D2PyMA]) were prepared by helix-sense-selective copolymerization with complexes of organolithium with (−)-sparteine [(−)Sp],(S, S)-(+)- and (R, R)-(−)-2,3-dimethoxy-1,4-bis(dimethylamino)butane [(+)- and (−)DDB], and (S)-(+)-2-(1-pyrrolidinylmethyl)pyridine [(+)PMP] as anionic initiators in toluene at low temperature. The copolymers obtained with (−)Sp and (+)DDB or (−)DDB complexes of organolithium showed low optical activity, but to [(+)PMP] complex with N,N′-diphenyleneamine monolithium amide [(+)PMP–DPEDA–Li)] was effective in synthesizing copolymers of high optical rotation ([α] about +320 to + 370°) which were comparable to those of corresponding homopolymers with one-handed helical structure. The optical rotations of poly[TrMA-co-PB2PyMA] and poly[TrMA-co-D2PyMA] were much more stable than that of poly(D2PyMA) or poly(PB2PyMA) in a solution of CHCl₃–2,2,2-trifluoroethanol (10 : 1, v/v) at 25°C, but optical rotation of poly[D2PyMA-co-PB2PyMA] slowly decreased with time in the same conditions. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2127–2133, 1998     

A practical, fast, and high-yielding aziridination procedure using simple Cu(II) complexes containing N-donor pyridine-based ligands

Four-coordinate dichlorocopper(II) complexes derived from di(2-pyridyl)methanes or pyridine itself exhibit high catalytic activity in aziridination of regular olefins with PhINTs in weakly coordinating chloroform in the presence of 1-2 equiv of NaBArF4 (BArF4- = tetra[3,5-di(trifluoromethyl)phenyl]borate). High yields of aziridines exceeding 90% can be obtained with a 1:1 olefin/PhINTs ratio and 1-5 mol % catalyst loading for such reactive olefins as styrene, tri- and tetramethylethylene. For cis-cyclooctene, indene, methyl acrylate, methyl methacrylate, vinyl methyl ketone, tert-butylethylene, and neopentylethylene, as well as for 1-hexene and cyclopentene, yields of corresponding aziridines vary from 44% to 83%. The catalytic activity and efficiency of the reported copper complexes decrease moderately in the absence of NaBArF4.