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An efficient and eco-friendly procedure has been developed for the synthesis of various 2,2’-arylmethylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) derivatives which were isolated and characterized by melting point, IR, 1H-NMR, 13C-NMR and mass spectrometric techniques. Out of the fourteen compounds synthesized, four compounds yielded crystals suitable for single crystal X-ray analysis which showed that 2,2’-phenylmethylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) crystallizes in the tetragonal system with space group I 4 1 /a, 2,2’-(3-nitrophenyl)methylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) crystallizes in the monoclinic system with space group P 2 1 /n, 2,2’-(4-nitrophenyl)methylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) crystallizes in the orthorhombic system with space group Pca21 and 2,2’-(4-chlorophenyl)methylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) crystallizes in the monoclinic space group P21/c.

Solid supported copper (0) nanoparticles were prepared by physical adsorption of copper (0) nanoparticles (synthesized through bottom-up approach) on the solid supports such as silica, HAP, cellulose and basic alumina. Studies comparing these supported catalysts were done with the synthesis of arylmethylene-bis-(3-hydroxy-2-cyclohexene-1-one) via the cascade Knoevenagel/Michael reaction. The highly efficient catalyst was characterized by spectroscopic techniques like XPS, TGA, EDX, SEM, TEM and AAS. The biological importance of arylmethylene-bis-(3-hydroxy-2-cyclohexene-1-one) enforced us to synthesize these compounds catalytically using solid supported copper (0) nanopartcles.

A mild and efficient reaction of the Bestmann-Ohira reagent with N-unprotected isatin-derived olefins has been developed for the selective synthesis of spiro-pyrazoline-oxindoles and tricyclic pyrazoles. The reaction features an attractive product-selectivity depending on the substituent on isatin-derived olefin. Treatment of 3-aryl/alkylideneoxindoles with BOR afforded spiropyrazoline-oxindoles, whereas 3-phenacylideneoxindoles furnished pyrazoloquinazolinones via a unique ring expansion reaction.

A novel, mild, green, fast, and highly regioselective one-pot protocol to prepare title compounds (III) is developed.

A variety of pyrrolidinyl oxyindoles are synthesized from one-pot reaction of isatin derivatives [(I) and (V)], proline (II), and terminal alkynes with aromatic or ester substituents [(III) and (VII)].

We present a metal-free method for the synthesis of imides by the direct coupling of NH-amides with methylarenes under iodine/aqueous TBHP conditions. The optimized conditions worked very well with benzaldehydes and benzyl alcohol and furnished the corresponding imides in good to excellent yields. A series of control and radical scavenger experiments were also performed, which suggested the involvement of radical pathways. The labeling experiment in the presence of 18O-labeled H2O suggested water as a source of oxygen in the imides.

21 Tetrahydroisoquinoline derivatives of type (IV) or (VII) are prepared by a one-pot three-component reaction comprising the formation of a C—N, a C—C and a C—O bond.

An efficient and green methodology for syntheses of various styryl-pyrazoles (3) from the reaction of 2-(5-phenyl-1H-pyrazol-3-yl)acetonitriles (1) with substituted benzaldehydes (2) by the use of biodegradable, nonhazardous, naturally occurring, and inexpensive choline chloride and NaOH under an environmentally benign medium has been described.

An expeditious, one-pot, N-iodosuccinimide-promoted reaction has been developed for the synthesis of 3-aroylimidazo[1,2-a]pyridines from 3-phenylpropiolaldehyde and 2-aminopyridines.This aminooxygenation process of alkynes is general and was successfully extended to access 3-aroylimidazo[1,2-a]pyrazines and 3-aroylimidazo[1,2-b]pyridazines. With the metal-free conditions and great efficiency in expanding molecule diversity, this method is superior to the existing procedures in the synthesis of 3-aroylimidazo[1,2-a]-N-heterocycles.

A new series of heterometallic 3d–4f sandwich type phosphotungstates, [Ln{PCo2W10O38(H2O)2}2]11– (Ln = SmIII, EuIII, GdIII, TbIII, DyIII, HoIII, ErIII, TmIII, YbIII, and LuIII, denoted 1a–10a, respectively), have been synthesized by a one-pot reaction procedure on reacting the dilacunary K14[P2W19O69(H2O)]·24H2O precursor with Ln(NO3)3·nH2O and Co(NO3)2·6H2O in an aqueous potassium chloride solution. All the compounds were isolated as potassium salts and further characterized with different analytical techniques such as single-crystal X-ray diffraction, Fourier transform infrared spectroscopy, high-resolution electrospray ionization mass spectrometry, elemental analysis by inductively coupled plasma atomic emission spectroscopy, magnetic measurement, and thermogravimetric analysis. Single-crystal X-ray diffraction analysis of the compounds reveals that all these compounds are isostructural and crystallized in the orthorhombic crystal system in space group Iba2. The polyanions contain the α-1,5 isomer of d...

Copper(I)-promoted 5-exo halogen-atom-transfer radical cyclization of 2,2,2-trihaloethylallyl sulfides gave highly functionalized tetrahydrothiophenes in good to high yields. Stereochemical aspects of the diastereomeric mixtures of products formed under different reaction conditions were evaluated, and single-crystal diffraction analysis and 2D NMR spectroscopic analysis were carried out. The synthetic application of α-acetoxy tetrahydrothiophenes in the preparation of a dihydrothiophene has also been demonstrated.

A simple, facile, and environmentally benign intramolecular dehydrogenative coupling of various 1,2-diarylethylenes for the synthesis of phenanthrenes in excellent yield has been described. This new methodology uses ceric ammonium nitrate (CAN) as a promoter at room temperature and has been extended to intermolecular synthesis of biaryl compounds. The electron transfer from methoxyarene to cerium leads to cationic radical formation, which further proceeds to intramolecular coupling. Preliminary mechanistic investigation by EPR spectroscopy and density functional theory calculation suggested a similar view.

The domino aldol/hetero-Diels–Alder synthesis of some new tricyclic pyrano[3,4-c]chromene derivatives has been achieved successfully after assembling a variety of acyclic or cyclic monoketones with prenyl ether-tethered aldehydes in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene in glycerol at 120 °C. The hitherto unreported stereochemical outcome of this synthetic sequence was studied and established on the basis of single-crystal X-ray diffraction data and 2D NMR NOESY spectroscopy along with the isolation and characterization of the intermediate Aldol condensation product.

A series of novel alkyl 5-hydroxy-7-aryl-5-methyl-1,3-dioxo-2-phenyl hexahydropyrazolo[1,2-a][1,2,4]triazole-6-carboxylates and alkyl 5-aryl-7-methyl-1,3-dioxo-2-phenyl-1,2,3,5-tetra hydropyrazolo[1,2-a][1,2,4]triazole-6-carboxylates have been synthesized. The synthesis of hydroxy pyrazolo[1,2-a][1,2,4]triazoles has been achieved by DBU mediated one pot reaction of aromatic aldehydes, alkyl acetoacetates and 4-phenylurazole at 35 °C in ethanol–water (1:1). Dehydration of hydroxy pyrazolo[1,2-a][1,2,4]triazoles has been achieved using conc. H2SO4 to afford dehydrated pyrazolo[1,2-a][1,2,4]triazoles in high yields. The structural assignments have been made by spectral data and unambiguously confirmed by X-ray analysis. Good yields, operational simplicity and moderate conditions are the advantages of the reactions.

New quaternary Heusler materials, CoMnTiAl and FeMnTiAl, have been investigated. These alloys are found to be stable in a ferromagnetic phase in Y1 type structure; the stability is also confirmed by various conditions of elastic constants. Both alloys show half-metallic (HM) ferromagnetic character with integer magnetic moments and they present a metallic nature. The values of the minority band gap in CoMnTiAl and FeMnTiAl are found to be 0.50 eV and 0.25 eV respectively. These alloys also possess excellent thermoelectric behaviour with Seebeck coefficients for CoMnTiAl (FeMnTiAl) as 31 μV K−1 (20 μV K−1) at room temperature. Here we report that CoMnTiAl achieves a figure of merit of 0.62 in a wide temperature range while FeMnTiAl achieves 0.77. Thus these new quaternary Heusler alloys can prove to be ultimate candidates for spin valves and for the best thermoelectric applicability over an ample temperature range.

The title reaction involves consecutive glycosidation and azide alkyne cyclization under one-pot conditions using a combination of AgOTf and Cu(0) catalyst.

A simple and efficient protocol has been developed for the synthesis of 5-substituted 1H-tetrazole derivatives in good to excellent yields from various oximes and sodium azide by using indium(III) chloride as a Lewis acid catalyst. The present method has significant advantages, such as an inexpensive catalyst, low catalyst loading, mild reaction conditions, and simple experimental procedures.

Electrophilic activation of alkynylphosphine oxides and phosphonates provides a novel approach to the synthesis of P-substituted and P-centered heterocycles. Iodocyclization affords a heteroaryl iodide that can, among other things, be used in reiterative alkyne coupling and iodocyclization to give cyclic phosphonates and other cyclization reactions to give π-rich P-heterocycles.

An efficient and practical method for the chemoselective ipso-hydroxylation of arylboronic acids is demonstrated using urea-hydrogen peroxide under catalyst free condition at room temperature. Remarkably, oxidation sensitive functional groups such as olefin, aldehyde, alcohol, ketone, and sulfide as well as heterocycles such as pyridine and thiophene were tolerated under the standard reaction condition. In addition to the solution phase, a solid phase ipso-hydroxylation of arylboronic acids has been investigated with urea hydrogen peroxide. The scope and limitations of the solid phase protocol is discussed.

A series of N-nitrosamines is synthesized from the corresponding secondary amines using tert-butyl nitrite under solvent-free conditions.

Molecular nanomagnets encompass a wide range of coordination complexes possessing several potential applications. A formidable challenge in realizing these potential applications lies in controlling the magnetic properties of these clusters. Microscopic spin Hamiltonian (SH) parameters describe the magnetic properties of these clusters, and viable ways to control these SH parameters are highly desirable. Computational tools play a proactive role in this area, where SH parameters such as isotropic exchange interaction (J), anisotropic exchange interaction (Jx, Jy, Jz), double exchange interaction (B), zero-field splitting parameters (D, E) and g-tensors can be computed reliably using X-ray structures. In this feature article, we have attempted to provide a holistic view of the modelling of these SH parameters of molecular magnets. The determination of J includes various class of molecules, from di- and polynuclear Mn complexes to the {3d-Gd}, {Gd–Gd} and {Gd-2p} class of complexes. The estimation of anisotropic exchange coupling includes the exchange between an isotropic metal ion and an orbitally degenerate 3d/4d/5d metal ion. The double-exchange section contains some illustrative examples of mixed valance systems, and the section on the estimation of zfs parameters covers some mononuclear transition metal complexes possessing very large axial zfs parameters. The section on the computation of g-anisotropy exclusively covers studies on mononuclear DyIII and ErIII single-ion magnets. The examples depicted in this article clearly illustrate that computational tools not only aid in interpreting and rationalizing the observed magnetic properties but possess the potential to predict new generation MNMs.

CuFe2O4 superparamagnetic nanoparticles were used as an efficient heterogeneous catalyst for the one-step synthesis of dibenzodiazepinones via Ullmann type coupling reaction. The catalyst was highly stable, efficient and easily synthesized from readily available starting materials. The prepared CuFe2O4 NPs was characterized using various characterization techniques such as TEM, SEM, EDX, XRD, VSM, XPS and FT-IR analysis. The thermal stability of the catalyst was also examined by TGA analysis. The present methodology eliminates the multistep procedure for the synthesis of the said compounds. The catalyst efficiently catalyzed the reaction under milder condition furnishing high yield of the product within a short reaction time with higher regioselectivity. Furthermore, the CuFe2O4 super paramagnetic nanoparticles could be easily separated by an external magnet and reused for four consecutive runs. The present protocol is devoid of any base or ligands and showed excellent result for reproducibility and gram scale reaction which addressing the issues of sustainability and environment friendliness.

Catalysts based on bimetallic nanoparticles have received tremendous scientific and industrial attention and are established as an important class of active catalysts. These catalysts displayed improved catalytic activities compared to their monometallic counterparts for several reactions, which is attributed to their highly modified surface structures (electronic and geometrical) due to the synergic cooperation between the two metals of the bimetallic nanoparticle catalyst. Moreover, such synergic interactions are more prominent in alloy nanoparticle catalysts, where the probability of metal-to-metal interactions is higher in comparison with other systems (such as core–shell nanoparticles). This minireview highlights the recent progress made in the last decade towards the development of activated bimetallic alloy nanoparticle catalysts for C–C coupling reactions, including asymmetric C–C bond coupling reactions. Herein, the influence of the modified electronic structures of the newly formed bimetallic alloy nanoparticle catalysts on their activated catalytic performance is also discussed extensively.

A ligand-free Pd-catalyzed approach has been developed for the synthesis of dibenzo-fused naphthyridines. The reaction involves a one-pot domino sequence of reactions involving C–H functionalisation and oxidation. The reaction was applicable to a wide range of substrates, giving the required product. Further fluorescence studies were performed where the Stoke's shift was found to be dependent on the polarity of the solvent.

A tandem one pot reaction involving gem-dichlorination, hydrolysis and nitrile oxide generation from 7-alkoxy-4-chloro-2,2-dimethyl-2H-chromene-6-carbaldehyde oxime followed by olefin/alkyne cycloaddition has been carried out in good yield at ambient temperature using open flask chemistry. The synthesized 4-chromanone derivatives show conformational isomerism as determined by VT 1H-NMR, confirmed by X-ray crystallography and explained by DFT calculations. This can be a general method for C-3 electrophilic chlorination of benzopyran derivatives.

Copper(I)/ligand-catalyzed one pot synthesis of highly substituted 2,3-difunctionalized-4-chlorofurans has been reported. The reaction proceeds via a Cu(I)-catalyzed regioselective 5-endo-trig radical cyclization of 2,2,2-trichloroethyl vinyl ethers followed by the base-promoted dehydrochlorination. The success of the kinetically disfavored 5-endo cyclization was attributed to the formation of captodatively stabilized radical intermediate in the cyclization step and relatively high reaction temperature. Synthetic application of this protocol was also demonstrated in the preparation of alkyl and aryl substituted 4-chlorofuranonapthoquinones.

We report an efficient procedure for the synthesis of symmetrical disulfanes from organic thiocyanates in the presence of sodium in silica gel at room temperature. By avoiding the use of foul-smelling thiols, the present protocol provides an attractive alternative to existing methods for the preparation of symmetrical disulfanes.

Schiff’s bases an important class of N containing compounds is gaining much interest in field of coordination and medicinal chemistry. Dehydroacetic acid (DHA) based Schiff’s bases and their complexes with various metal ions were found to be of great interest due to their immense biological and physico chemical properties. The survey updates and highlights the synthesis, spectral features, catalytic and biological significance of various Schiff’s bases designed on dehydroacetic acid and their metal complexes till now.

Here, we review the advances in understanding the structure and properties of magnetoelectric gallium ferrite (GaFeO3 or GFO). Special significance of GFO lies in its compositional tunability over a large range of Ga:Fe ratio without forming a second phase which also renders prospective room temperature magnetoelectricity in the material. Detailed structural studies show noncentrosymmetric orthorhombic Pc21n symmetry without any structural phase transition between 4 K and 700 K. The material shows a ferrimagnetic behavior driven by cation site disorder, corroborated both experimentally as well as theoretically, with transition temperature dependent upon Ga:Fe ratio. GFO exhibits magnetostructural and magnetoelectric coupling indicating coupling among the structural, magnetic and electrical degrees of freedom which could possibly be utilized to strain engineer electrical and magnetic properties in the thin film structures. However, the biggest challenge remains to reduce the leakage in the material in both...

A cyclization of chalcones with guanidine yields benzo[h]quinazolines which can be easily further converted to compounds (VII) or (IX).

A series of 3,7-diaryl-6,7-dihydro-5H-6-substituted-thiazolo[3,2-a]pyrimidin-5-ones (3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, 3i, 3j) were synthesized by the [4+2] cycloaddition reaction of 2-arylideneamino-4-arylthiazoles (2a–j) with in situ generated monosubstituted ketenes under PTC conditions coupled with ultrasonication in good to excellent yields. All the synthesized compounds were characterized on the basis of their spectral (IR, PMR, and Mass) and analytical data. The synthesized compounds were also screened for their insecticidal activity against Helicoverpa armigera and some of them showed promising activity.

Proton transfer reactions are advantageously investigated in low-dielectric-constant apolar aprotic solvents where specific solute–solvent interactions are greatly minimized, if not eliminated, and proton transfer occurs directly. An intriguing feature of these reactions is their general acid/base-catalyzed kinetics with a timescale over microseconds to minutes. Proton-coupled electron transfer (PCET), a great promise in the development of renewable energy sources, is an emerging application of the reactions. This article is an updated review of the post-1980 developments in understanding the mechanism of proton transfer reactions, quantitative structure–reactivity relationships, acid/base-catalyzed molecular rearrangements, reverse trends between acidity parameters and 13C δco (a measure of electron population at the carboxyl carbon) in aromatic carboxylic acids, coupling of proton transfer with electron transfer, and PCET reactions in suitably designed model systems in apolar aprotic solvents for renewable energy devices. Copyright © 2015 John Wiley & Sons, Ltd.

A new one-pot three-component green approach has been developed for the synthesis of a series of pyrazolone derivatives 2(a–s) from differently substituted aromatic aldehydes, ethylacetoacetate and phenylhydrazine/2,4-dinitrophenylhydrazine in excellent yields (94–98%), employing SiO2/ZnBr2 as a recyclable Lewis acid catalyst in water under microwave heating. The molecular structure of compounds 2a and 2d were well supported by single crystal X-ray crystallographic analysis. The present protocol bears a wide substrate tolerance and is believed to be more practical, efficient, eco-friendly and compatible as compared to existing methods.

Ultrasonic-assisted, catalyst-free reactions of ninhydrin with ethyl cyanoacetate and diethyl malonate led to the unprecedented formation of an indenopyran and a spiroindenofuran viz. diethyl 4-cyano-2-hydroxy-5-oxo-4,5-dihydroindeno[1,2-b]pyran-3,4-dicarboxylate 1 and diethyl 3a′,8b′-dihydroxy-1,3,4′-trioxo-1,3,3a′,4′-tetrahydrospiro[indene-2,2′-indeno[1,2-b]furan]-3′,3′(8b′H)-dicarboxylate 3, respectively. In addition to these unprecedented results, reactions of ninhydrin with dimedone, ethyl acetoacetate and ethyl nitroacetate yielded 4b,9b-dihydroxy-7,7-dimethyl-7,8-dihydro-4bH-indeno[1,2-b]benzofuran-9,10(6H,9bH)-dione 5, ethyl 3a,8b-dihydroxy-2-methyl-4-oxo-4,8b-dihydro-3aH-indeno[1,2-b]furan-3-carboxylate 6 and 2-hydroxy-2-(nitromethyl)-1H-indene-1,3(2H)-dione 7, respectively. The structures of 1, 3, 5, 6 and 7 were determined by X-ray crystallography and attempts have been made to propose the mechanism of their formation.

One-pot synthesis of 2-aroylindoles and 2-arylquinolines has been achieved by the reductive cyclization of 3-(2-nitrophenyl)-1-arylprop-2-en-1-ones with triethylphosphite [P(OEt)3] under microwave irradiation. The formation of 2-arylquinolines by this method is unprecedented.

The two-step, one-pot procedure involves an amino-catalytic direct Mannich reaction/cyclization sequence followed by an IBX-mediated chemo- and regioselective oxidation.

Polycrystalline TbNiGe2 is prepared by arc melting of the elements followed by annealing (evacuated quartz tubes, 800 °C, 7 d).

This is the first method for the reaction of arylglyoxals with alkylthiols under metal-free conditions to give the title compounds.

A variety of functional groups can be introduced in the phenanthridine skeleton following the 3-component strategy shown.

Furans are an important class of compounds and exhibit a diverse range of activities and properties. As such, improved synthetic access to furans is an important research goal. In the present report, a solvent- and catalyst-free reaction between 5,5-dimethyl-1,3-cyclohexanedione (dimedone), an aryl aldehyde and an isocyanide under microwave irradiation is presented. This method is significantly improved from previously described protocols in terms of applicability of wide ranging aryl aldehydes, better yields, shorter reaction times, facile work up and essentially no need of column chromatography. The photophysical properties of this series of compounds were studied for their possible applicability in the field of metal ion sensors. In solution, two compounds, 2-(cyclohexylamino)-3-(1H-indol-3-yl)-6,6-dimethyl-6,7-dihydrobenzofuran-4(5H)-one (1 i) and 2-(tert-butylamino)-3-(1H-indol-3-yl)-6,6-dimethyl-6,7-dihydrobenzofuran-4(5H)-one (1 j), underwent an observable color change from yellow to colorless in the presence of aluminum(III) ions. Further studies to investigate the UV absorption and luminescence behavior of these compounds revealed their utility as "naked-eye sensors" for aluminum detection.

A series of sandwich-type early lanthanoid substituted complexes: [Ln(α-GeW11O39)2]13− [Ln = LaIII (La-1) and CeIII (Ce-2)] and acetate-bridged hybrid dimeric complexes: [{Ln(μ-CH3COO)GeW11O39(H2O)}2]12− [Ln = PrIII (Pr-3), NdIII (Nd-4) and SmIII (Sm-5)] were synthesized by the interaction of a trilacunary Na10[GeW9O34]·18H2O precursor with Ln(NO3)3·nH2O in a potassium acetate buffer at pH 4.7. All these compounds were isolated as mixed sodium/potassium salts and structurally characterised by various analytical techniques such as single-crystal X-ray diffraction, FT-IR, ICP-AES, UV/vis, photoluminescence spectroscopy, thermogravimetric analysis, 13C and 1H NMR spectroscopy, magnetism and electrochemistry. The FT-IR spectra suggest that compounds (La-1a and Ce-2a) and (Pr-3a–Sm-5a) are isomorphous. We also synthesized analogous acetate-bridged dimeric complexes (Pr-3a to Sm-5a) with mid and late lanthanoid ions (Ln = EuIII, GdIII, TbIII, DyIII, HoIII, ErIII, TmIII and YbIII) using a procedure published elsewhere and also investigated other features such as electrochemistry and magnetic and photochromic properties. The molecular complexes Pr-3a, Sm-5a, Eu-6a, Tb-8a, Dy-9a, Ho-10a, Er-11a and Tm-12a show good photochromic behaviour at room temperature. Magnetic studies of La-1a, Ce-2a, Pr-3a, Nd-4a and Sm-5a were performed at room temperature and the molecular complexes were found to exhibit ferromagnetic behaviour.

Cu2ZnMS4-x (M: Al, Ga, In) nanocrystals are prepared by the colloidal hot-injection method starting with thermal decomposition of a 2:1:1 molar mixture of Cu(acac)2, Zn(acac)2, and M(acac)3 in oleylamine under N2 (Schlenk line, 150 °C) followed by quickly injecting a mixture of n-dodecanethiol and tert-dodecanethiol and subsequent heating (250 °C, 1 h), with the latter leading to a structural transition from the wurtzite to the stannite phase.

Various primary aryl, heteroaryl, aliphatic, alicyclic, and allylic alcohols are obtained in a simple two-step, one-carbon homologation of primary alcohols or reductive homologation of aldehydes using the Jocic-type reaction of trichloromethyl carbinols as key reaction.

A bio-based green solvent, lactic acid, is found to be an efficient reaction medium for the catalyst free oxidation of arylboronic acids into phenols with aqueous hydrogen peroxide. Various substituted arylboronic acids have undergone ipso-hydroxylation smoothly at room temperature to provide corresponding phenols in excellent yields. Remarkably, the oxidation susceptible functional groups such as sulphide, ketone, aldehyde and olefin are tolerated under the reaction conditions. Over all, lactic acid showed higher efficiency as a solvent medium when compared with conventional acetic acid.

A new, facile, regioselective ceric ammonium nitrate (CAN)-mediated one-pot access to bridgehead hydrazine bicyclic cationic structures with 2,3-dihydro-1H-pyrazolo[1,2-a]pyrazol-4-ium cations and [Ce3+(NO3)6]3− anion has been developed. The approach comprises [3+2]-cycloaddition of (2-bromo-2-nitrovinyl)arenes to N,N-cyclic azomethine imines, generated in situ by diaziridine ring opening in 6-Ar-1,5-diazabicyclo[3.1.0]hexanes or by metathesis of initially formed azomethine imine, followed by one-pot aromatization of the formed pyrazolidine ring.