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The Staudinger ketene-imine cycloaddition reactions of cyclobrassinin phytoalexin analogues 2-aryl-4,9-dihydro-1,3-thiazino[6,5-b]indoles with chloroacetyl chloride as a ketene source were investigated under different conditions. Both β-lactam ring formation and the N-chloroacetylation of the indole moiety took place. The indole N-chloroacetyl group can be easily removed by treatment in the presence of silica gel in methanol at reflux temperature. The selective β-lactam formation can be also achieved in certain cases under milder Staudinger conditions. The treatment of azeto[2,1-b]thiazino[6,5-b]indole-1-one derivatives with sodium ethoxide in ethanol provided the novel thiazepino[7,6-b]indole ring systems in a one-step ring transformation. The structures of the new ring systems were determined by means of IR and NMR spectroscopy.

Ketene–imine cycloaddition reactions between cis - and trans -2-aryl-4a,5,6,7,8,8a-hexahydro-4 H -3,1-benzothazines and chloroacetyl chloride in the presence of base were investigated. Because of the diastereotopic C N faces of cyclohexane-condensed thiazines, both of the possible Staudinger addition product monochloro-β-lactam stereoisomers were obtained for both the cis and the trans compounds. The novel azetidin-2-ones were transformed into the corresponding 3-ethoxycarbonyl-2-aryl-1,5,5a,6,7,8,9,9a-octahydro-4,1-benzothiazepines with sodium ethoxide in a one-step procedure. Structural and stereochemical analyses of the synthesized compounds were carried out by means of IR and NMR spectroscopy.

The potential of a series of cinchona-based organocatalyst candidates was investigated by comparative DFT analysis of the crucial bond-forming step of the enantioselective Michael addition of nitromethane to 1,3-diphenylpropenone. It was shown that the applied methods are feasible to investigate the influence of functional groups on the activation electron energy. Besides the well known interaction of the substrates with the urea and quinuclidine moiety the significance of π stacking- and H-bonding interactions between the electrophilic component and the catalyst are also pointed out. Due to the π stacking the replacement of the widely appreciated trifluoromethyl groups by nitro groups allows the interacting rings to get closer lowering the activation barrier of the crucial C–C bond formation step.

The ring transformations of dichloro-β-lactam-fused 2-aryl-1,3-benzothiazines with sodium methoxide were investigated. With 2 equiv of base, the dichloro-β-lactam derivatives underwent rearrangement and dihydro-1,4-benzothiazepines, 3,4-substituted isoquinolines and substituted thiazole disulfides were isolated. A possible reaction mechanism is proposed for the simultaneous formation of the novel products. The formation of isoquinoline and thiazole derivatives can be explained by sulfur extrusion and addition sequences.

Cyclic chalcone analogues (2–5) and their ferrocenyl counterparts (6–10) were synthesized and their logP and P388 cyctotoxity were investigated. The structures of the newly synthesized compounds were confirmed by IR 1H and 13NMR spectroscopy. Comparison of conjugation and stereochemistry of the respective derivatives showed similar characteristics compared to ones with some higher degree of conjugation in the ferrocenyl series. Comparison of logP of the ferrocenyl derivatives determined by a validated RP-TLC method showed the ferrocenyl derivatives to have higher logP TLC. The results demonstrate that the differences in three dimensional shape, conjugation and lipophilicity do not have strong influence on the P388 cytotoxicity of the investigated phenyl (1−5) and ferrocenyl (6−10) enones.

Chiral salen complexes with C2-symmetry were prepared by the complexation of a selection of transition metal salts with a novel ligand obtained via controlled diastereoselective diaza-Cope rearrangement of a diimine which was resulted from the condensation 2,2′-[(1R,2R)-1,2-diaminoethane-1,2-diyl]diphenol with formylferrocene. On the effect of air the iron(II)-complex dissolved in DCM underwent oxidation affording a square pyramidal iron(III)-complex with coordinated chlorine atom in the apical position. It was also found that the two ferrocenyl groups present in the cobalt(II)-complex remained intact in the course of iodine-mediated oxidation leading a diamagnetic cobalt(III)-complex. The structures of the new compounds were established by single crystal x-ray diffraction as well as IR 1H-, 13C- and 15N NMR spectroscopy.

A series of novel functionalized mono-, bis- and tris-(S)-{[(2S,4R,8R)-8-ethyl-quinuclidin-2-yl](6-methoxyquinolin-4-yl)}methanamines including ferrocene-containing derivatives was obtained by the reaction of the precursor amine with a variety of acylation agents. Their in vitro antitumor activity was investigated against human leukemia (HL-60), human neuroblastoma (SH-SY5Y), human hepatoma (HepG2) and human breast cancer (MCF-7) cells by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)-assay and the 50% inhibitory concentration (IC(50)) values were determined. Our data indicate that the precursor amine has no antitumor activity in vitro, but the bis-methanamines with ureido-, thioureido and amide-type linkers display attractive in vitro cytotoxicity and cytostatic effects on HL-60, HepG2, MCF-7 and SH-SY5Y cells. Besides 1H- and 13C-NMR methods the structures of the new model compounds were also studied by DFT calculations.

ortho-Nitrophenyl-substituted condensed 1,3-benzothiazines proved to be a useful core unit in indole syntheses under non-reductive conditions. Thus, the treatment of ortho-nitro-2-aryl-2a-chloro-4H-azeto[2,1-b][1,3]benzothiazin-1-ones with sodium methoxide in methanol provided indolo-1,4-benzothiazepines via a novel rearrangement. Through the sulfur extrusion reaction of indolo[2,3-b][1,4]benzothiazepines, further alkaloid-type indole derivatives, indolo[3,2-c]isoquinolines, were obtained. The structures of the new ring systems were determined by means of NMR spectroscopy.

all-endo-3-amino-5-hydroxybicyclo[2.2.2]octane-2-carboxylic acid (13) and all-endo-5-amino-6-(hydroxymethyl)bicyclo[2.2.2]octan-2-ol (10) were prepared via dihydro-1,3-oxazine or gamma-lactone intermediates by the stereoselective functionalization of an N-protected derivative of endo-3-aminobicyclo[2.2.2]oct-5-ene-2-carboxylic acid (2). Ring closure of beta-amino ester 4 resulted in tricyclic pyrimidinones 15 and 16. The structures, stereochemistry and relative configurations of the synthesized compounds were determined by IR and NMR.

Compound (IIb) shows moderate in vitro anti proliferative action against squamous skin carcinoma cell line (A431).

We report a convenient approach for the synthesis of a new ring system: 4,5-dihydro-1,3-thiazino[5,4-b]indoles. The procedure involves the use of Lawesson's reagent in the presence of silica to achieve the one-step ring-closure reactions of 2-benzoylamino-3-hydroxymethylindole intermediates to furnish 4,5-dihydro-2-aryl-1,3-thiazino[5,4-b]indoles. 2-Phenylimino-1,3-thiazino[5,4-b]indoles were obtained via the corresponding 3-phenylthiourea-2-carboxylic acid ester derivatives by chemoselective reduction of the ester group, followed by ring closure under acidic conditions. The structures of the novel products were elucidated by IR, 1H-NMR, and 13C-NMR spectroscopy, including 2D-HMQC, 2D-HMBC, and DEPT measurements. J. Heterocyclic Chem., (2011).

The ring-enlargement reactions of monochloro-β-lactam-fused 2-aryl-1,3-benzothiazines revealed that the reactions of ortho-nitro aryl-substituted derivatives with sodium methoxide in methanol provided two products, depending on the amount of the base. With 2 equiv of reagent, the expected 1,4-benzothiazepines were obtained. Somewhat surprisingly, treatment with a large excess of sodium methoxide led to the formation of indolo-1,4-benzothiazepines via a novel rearrangement. The structures of the new ring systems were determined by means of X-ray crystallography and NMR spectroscopy.

A series of novel aryl-substituted β-lactams condensed with 1,3-benzothiazines, isoquinolines or 1,4-benzothiazepine were obtained by means of the Staudinger reaction and isomerized in the presence of sodium methoxide to the thermodynamically more stable form. The structures of the new molecules were determined by NMR spectroscopy. Theoretical calculations corroborate the experimentally observed structure–reactivity relationships.

A convenient synthesis was devised for rare 2,3-disubstituted 4,5-dihydro-1,4-benzothiazepines from 2-aryl-4H-1,3-benzothiazines. The Staudinger reaction of 1,3-benzothiazines obtained with chloroacetyl chloride selectively furnished trans-monochloroβ-lactam-condensed thiazines. The ring expansion of azeto[2,1-b][1,3]benzothiazin-1-one derivatives with sodium methoxide afforded 1,4-benzothiazepines as the sole product in good yields. The structures of the new molecules were proved by means NMR and IR spectroscopy.

A series of novel ferrocene-containing-dihydropyrimidines (DHPs) were prepared by three-component Biginelli reactions of formylferrocene, 1,3-dioxo-components and thiourea catalyzed by boric acid and ytterbium triflate, respectively. When cyclic-1,3-diones were employed as dioxo component in the reactions promoted by boric acid, besides one expected 4-ferrocenyl-2-thioxoquinazoline, 9-ferrocenyl-2 H -xanthene-1,8-dione and 9-ferrocenylcyclopenta[ b ]chromen-8-ones could also be isolated as products. By means of control reactions and B3LYP/6-31 G(d) modelling the formation of the chromenone was interpreted by hetero-Diels–Alder addition involving the Knoevenagel intermediate and the cyclopentadiene resulted in situ from acid-catalyzed decomposition of formylferrocene. The enhanced tendency of the acyclic dioxo components to undergo Biginelli reaction avoiding cycloaddition was reasoned by the formation of Knoevenagel intermediates capable of chelating proton or Lewis acids. The structures of the new compounds were established by IR and NMR spectroscopy, including HMQC, HMBC, DEPT and DNOE measurements. Some structural characteristics were disclosed by B3LYP/6-31 G(d) method.

The desmotropy of differently substituted (R∗)-3-ethoxycarbonyl-2-aryl-3,5-dihydro-4,1-benzothiazepines and 3-ethoxycarbonyl-2-aryl-1,5-dihydro-4,1-benzothiazepines was investigated. The target 4,1-benzothiazepines were obtained via the ring transformation of (2R∗,2aS∗)-2-chloro-2a-aryl-2,2a-dihydro-2H,4H-azeto[1,2-a][3,1]benzothiazin-1-ones with sodium ethoxide in ethanol. The β-amino ester intermediate of the ring-enlargement reaction was isolated. Surprisingly, the desmotropes obtained could be separated by column chromatography and proved to be unexpectedly stable in solution. Further comparative studies revealed the existence of only the enamine forms of regioisomeric 2-ethoxycarbonyl-3-aryl-4,5-dihydro-7,8-dimethoxy-1,4-benzothiazepine derivatives; in this case, no desmotropy occurred. The structures were proved by means of NMR and IR spectroscopy.

Substituted 2H-1,3-benzothiazines and 2,3-dihydro-1,4-benzothiazepines react with dimethyl acetylenedicarboxylate in aqueous methanol to give new, unexpected condensed-skeleton heterocycles. The structures of the new compounds were determined by 1H and 13C nuclear magnetic resonance (NMR), two-dimensional (2D) heteronuclear multiple-bond correlation (HMBC), infrared (IR), and for one derivative also by X-ray analysis.

Cyclocondensation of 1-phenyl-3-ferrocenyl-2-propen-1-one (1) with RNHNH2 hydrazines and the substituent-dependent product distribution were investigated. With methylhydrazine, formation of two regioisomeric pairs of pyrazolines and pyrazoles was observed. The ratio of the products varied with the solvent and temperature. Transformation of 5-ferrocenyl-N-substituted pyrazolines into pyrazoles was systematically studied and DDQ was found to be the most suitable reagent. Mechanism of the cyclization reactions taking place under kinetic- and thermodynamic controls was supported with DFT calculations. The energy-dependence of the transformation of pyrazoline to pyrazole was investigated also by EI MS. Structure determination of the new compounds was performed by IR, MS and NMR methods including 2D-HMQC, 2D-HMBC, DEPT and DIFFNOE measurements. For two compounds structures were also proved by X-ray diffraction.

Cyclization of 1,5-bis(ferrocenylmethylidene)thiocarbonohydrazide with DMAD afforded diastereomeric dimethyl-thiazole-4,5-dicarboxylates. The cis -isomer undergoes ring opening and recyclization to a thiazolone derivative. A further thiazolone was obtained from this precursor with ethyl chloroacetate employing a bifunctional organocatalyst. Due to its propensity to dehydrogenation evidenced by DFT calculations, the studied thiocarbonohydrazide underwent oxidative cyclizations under different conditions to yield a 1,3,4-thiadiazole and a 1,2,4-triazole derivative, respectively. Thermal isomerisation of 1,3,4-thiadiazole into 1,2,4-triazole was also observed. The DMAD-mediated cyclizations of the S-metylated thiocarbonohydrazide and the 1,5-bis(ferrocenylmethylideneamino)guanidine gave 1,2,4-triazole derivatives and a 4-pyrimidone, respectively. The structure of the new compounds was established by IR and NMR spectroscopy, including HMQC, HMBC and DEPT measurements. The solid state structure of a triazole was revealed by single crystal X-ray analysis.

A series of ferrocene-containing mono - and bis -dihydropyrimidines (DHP’s) were prepared by boric acid mediated three-component Biginelli reactions of formyl- and 1,1′-diformylferrocene, 1,3-dioxo-components and urea. A few further transformations including hydrogenolysis of a benzyl 4-ferrocenyl-DHP-5-carboxylate were also performed. Novel cis -fused saturated pyrimido[4,5- d ]pyrimidine-2,7(1 H ,3 H )-diones incorporating [3]-ferrocenophane moiety were constructed by means of iron(III)-catalyzed Biginelli-like condensations of 1,1′-diformylferrocene with urea and in situ generated methyl ketone-derived silyl enol ethers. The structures of the new compounds were established by IR and NMR spectroscopy, including HMQC, HMBC and DEPT measurements.

With DL-valinol, 3-amino-1-propanol and o-aminothiophenol, aroyl(bi/tri)cyclic lactones 1 and 2 were cy- clized to isoindole- 4-6, 8, 9, pyrimidinone- 10 or thiazepine- 7 condensed heterocycles. The ketal lactone 3 furnished the benzthiazoloisoindole 9 and mixtures of epimeric hydroxyphthalazinoquinazolinones 11 and 12. The structures were es- tablished by means of 1 H and 13 C NMR spectroscopy and in some cases by X-ray crystallography.

A highly efficient trifluoromethanesulfonic acid-mediated rearrangement of the benzoylaminomethylthio group of 3-benzoylaminomethylthioindoles (7a–e) to position 2 of the indole ring was developed. Thus, 2-benzoylaminomethylthioindoles (9a–e) were obtained in good yields and were involved as key intermediates in the synthesis of the new γ-carboline analogue ring system: 2,9-dihydro-4-aryl-1,3-thiazino[6,5-b]indole derivatives (11a–e). The target thiazinoindoles (11a–e) were prepared via 2-thiobenzoylaminomethylindoles (10a–e) in modified Bischler–Napieralski reactions.

An efficient and selective non-acidic protocol has been developed for the synthesis of derivatives of a new ring system: 4-aryl-1,3-thiazino[5,6-b]indole, a 4-thiaharmalan analogue. The convenient amidomethylation of indole-3-thiol (5) afforded 3-benzoylaminomethylthio-1H-indole (7a), with ortho-amidomethylated 2-benzoylamino-methyl-3-benzoylaminomethylthio-1H-indole (8) as side product. Following the Bischler–Napieralski reaction of 7a the rearranged 2-benzoylaminomethylthio-1H-indole 11 could be isolated. In order to prevent such rearrangements the target thiazinoindoles were prepared via 3-thiobenzoylaminomethylthioindole (13) via a modified Bischler–Napieralski reaction.

Cyclization reactions of the thiosemicarbazones of formyl- and acetylferrocene and their S -methyl derivatives with DMAD afforded novel ferrocenyl-hydrazono-substituted thiazolones, one–one dimethylthiazole-4,5-dicarboxylate and 1,3-thiazin-4-one, N -ferrocenylimino-pyrimidones/imidazolones, one intermediate β-adduct and via oxidative cyclization, a ferrocenyl-1,2,4-triazole. Ring isomerization of 1,3-thiazin-4-ones to a 1,3-thiazolones was detected. The structure of the new compounds was established by IR and NMR spectroscopy, including HMQC, HMBC and DEPT measurements and supported with GIAO NMR calculations and controlled also synthetically by phase-transfer methylation. For three compounds the stereostructure was also proved by X-ray diffraction.

Various γ-oxocarboxylic acids [aroylpropionic acids, cis-2-(4-methylbenzoyl)cyclohexanecarboxylic acid, diendo-3-benzoylbicyclo[2.2.1] heptane-2-carboxylic acid, formylbenzoic acid, methanobenzenecyclooctencarboxylic acid and the cyclopentadiene adduct of 3-trans-(4-methylbenzoyl)acrylic acid] were reacted with diexo-3-aminomethyl-7-oxabicyclo[2.2.1]hept-5-en-2-ylamine 2 to result in condensed pyrroloepoxyquinazolines 3–10. The starting 2 retained the diexo configuration, but cis → trans isomerization took place when cis-2-(4-methylbenzoyl)cyclohexanecarboxylic acid was applied. The structures, including the ring annelations and the position of the aryl group on the new chiral centre, were established by means of NMR spectroscopy, and in the cases of the trans-3-(4-methylbenzoyl)acrylic acid–cyclopentadiene adduct for 10a, 10b and 10c by X-ray crystallography.

Homogeneous catalytic carbonylation of some representative steroidal substrates (alkenyl iodides/enol triflates 1–5) has been carried out in the presence of (E)-1-(4′-aminophenyl)-3-ferrocenyl-prop-2-en-1-one (6) as the nucleophile. The products 1a–4a were obtained in moderate to good yield (43–75%) and were characterised with various spectroscopic methods (1H-, 13C NMR, IR, MS). The solid state structure of 17-(N-(4′-((2-ferrocenyl-ethenyl)-carbonyl)-phenyl)-carbamoyl)-5α-androst-16-ene (1a) has also been determined by X-ray crystallography.

Some new glycosides of 3-ferrocenyl-1-(4'-hydroxyphenyl)-prop-2-en-1-one were prepared and transformed into the corresponding pyrazoline and pyrazole derivatives. Using methyl-hydrazine, formation of regioisomers was observed. DDQ was found to be a mild and efficient reagent for the pyrazoline-pyrazole dehydroaromatization process. The structure of the new compounds was proved by IR and NMR spectroscopy. The in vitro antitumor activity of the substances was investigated against human leukemia (HL-60) cells by the MTT method. Among these new compounds some chalcone derivatives (3 a, 3 b, 5 a, and 5 b) showed attractive in vitro antitumor effects on human leukemia cells. These molecules contained ferrocenyl moieties and a p-hydroxy-phenolic ring or a size-independent apolar substitution of that.

Through the reactions of diexo-3-amino-7-oxanorbornene-2-carboxamide 1 with the oxocarboxylic acids: 4-oxopentanoic acid, p-chlorobenzoylpropionic acid or 2-formylbenzoic acid, the pyrrolo[1,2-a]pyrimidinediones 2 and 3 or pyrimido[1,2-a]isoindoledione 4 were formed on cyclization and thermolysis, when the parent cycles decomposed via the loss of furan to give 2–4 in a retro Diels–Alder reaction. With cis-or trans-2-aroylcyclohexanecarboxylic acids as starting compounds, the 1-aroylhexahydroisoindol-3-ones (5–8) were formed; the phenyl-substituted derivatives gave diastereomeric mixtures. The structures of the new compounds were established by NMR spectroscopy and, for 3 and 6, also by single-crystal X-ray structure determination.

A series of novel 3(5)-aryl/ferrocenyl-5(3)-phenothiazinylpyrazoles and pyrazolines were obtained by substituent-dependent regioselective condensation of the corresponding (E)-3-(2-alkyl-10H-phenothiazin-3-yl)-1-aryl/ferrocenylprop-2-en-1-one with hydrazine or methylhydrazine in acetic acid. The different propensity of the primary formed beta-hydrazino adducts to undergo competitive retro-Mannich reaction was interpreted in terms of tautomerisation equilibrium constants calculated by DFT using a solvent model. The regioselectivity of the cyclisation reactions with methylhydrazine and the substituent-dependent redox properties of pyrazolines were also rationalized by comparative DFT calculations performed for simplified model molecules. On the effect of ultrasound-promoted oxidation with copper(II)nitrate phenothiazine-containing pyrazolines, enones and oxo-compounds were selectively transformed into sulfoxides. Only one sulfoxide enone was partially converted into an oxirane derivative. The structure of the novel products was determined by IR and NMR spectroscopy including COSY, HSQC, HMBC and DNOE measurements.

6,7-Dimethoxy-2H-1,3-benzothiazine reacted with dimethyl acetylenedicarboxylate in aqueous methanol to give heterocycles with unexpected structures. A mechanism is proposed for the reaction.

All-endo-3-amino-5-hydroxybicyclo[2.2.1]heptane-2-carboxylic acid and two epimers of 3-amino-6-hydroxybicyclo[2.2.1]heptane-2-carboxylic acid were prepared via 1,3-oxazine or γ-lactone intermediates by the stereoselective functionalization of endo-3-aminobicyclo[2.2.1]hept-5-ene-2-carboxylic acid derivatives. Their structures were proved by IR and NMR spectroscopy, with the use of HMQC, HMBC, DEPT, and DIFFNOE techniques.

Cyclocondensation of 1-aryl-3-ferrocenyl-2-propen-1-ones (1) with hetaryl hydrazines resulted in N-hetaryl-3-aryl-5-ferrocenyl pyrazolines (3, 4). The analogous 3-aryl-1-ferrocenyl-2-propen-1-ones (5) gave the isomeric N-hetaryl-5-aryl-3-ferrocenyl-pyrazolines (6, 10), but in lower yield. The reaction of aryl-chalcones (7) with 4-hydrazino-phthalazinone led to 3,5-bis-aryl-N-hetaryl-pyrazolines (8) or to the corresponding ene-hydrazones (9). The structure of the new compounds was established by IR, 1H and 13C NMR spectroscopy, including DNOE, HMQC, HMBC and DEPT methods. For compounds 1b, 3b and 8b the stereo structure was elucidated also by X-ray diffraction.

An efficient non-reductive synthesis of 3-aminomethylindole ( 6 ) was developed from gramine ( 1 ) via 3-phthalimidomethylindole ( 2 ). The reactions of amine 6 with substituted methyl dithiobenzoates gave 3-(arylthiocarbonylaminomethyl)indoles. The Hugerschoff ring-closure reactions of the thiobenzamide intermediates ( 11a – f ) with phenyltrimethylammonium tribromide and subsequent basic treatment furnished 2-arylthiazino[6,5- b ]indole derivatives ( 14a – f ). By use of the latter bromine source, the phytoalexin cyclobrassinin ( 8 ) was prepared in a considerably higher yield than described previously. The structures of the novel products were elucidated by IR, 1 H and 13 C NMR spectroscopy, including 2D-HMQC, 2D-HMBC and DEPT measurements.

By means of base-catalysed condensation of 1-acyl-/1,1′-diacylferrocenes (acyl formyl or acetyl) with 3-formyl- and 3,7-diacetylphenothiazines a series of novel mono- and bis-chalcones were prepared. The enhanced reactivity of the enolate anions of the mono-chalcone intermediates relative to that of the enolates of the corresponding diacetyl-substituted precursor was interpreted by the electron-releasing effect of the ferrocenyl- or phenothiazinyl group present in the β position of the enone subunit. The structures of the novel products were evidenced by IR, 1 H and 13 C NMR spectroscopy including 2D-COSY, 2D-HSQC and 2D-HMBC measurements.

The reactions of di-endo- and di-exo-aminonorbornane/enecarboxylic acids 1–4 with ethyl 2-(2-oxocyclohexyl)acetate afforded methanoindoloquinolines 5, 6, 8, and 9, the oxo ester participating as a two-membered sp2 building block. In the cases of di-exo- and di-endo-aminonorbornenecarboxylic acids 2 and 4, methanoindolobenzoxazinediones 7 and 10 were also formed; compound 7 was also isolated from the mother liquor of 10. The reactions of ethyl 2-(2-oxocyclohexyl)acetate with aminonorbornane/enecarbohydrazides 11–14 result in the methanoquinazolophthalazines 15–18. The structures of the compounds were elucidated by NMR spectroscopy, and for 6, 7, 8, and 10 also by X-ray crystallography. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

Condensation reactions of 1,1'-diacetylferrocenes with hydrazine afford a series of novel ferrocenophanes with two incorporated ferrocene units. NMR spectroscopy is used to establish the free rotation of the –CH=N–N=C(R)– bridging chains (R = H, Me, Ph) and the rigidity of the –C(Me)=N–N=C(Me)– chain(s) in these macrocycles. The results of theoretical studies on molecular dynamics of these molecules carried out by density functional calculations are consistent with the spectroscopic observations. The stereostructures of the new compounds were confirmed by IR, 1H and 13C NMR spectroscopy, including 2D-COSY, 2D-HMQC and 2D-HMBC measurements, and by mass spectrometry. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

New classes of sugar derivatives of the antibacterial drug norfloxacin (1) were synthesized by substituting the N‐4′ of the piperazinyl moiety of the molecule. Direct coupling with gluco‐ and galactopyranosyl units afforded glycosylamines 2–5. Introduction of urea or thiourea linkage between glycosyl and norfloxacin units was produced with the corresponding glycosyl isocyanates or isothiocyanates. For the synthesis of unprotected sugar urea compounds, a new approach was applied by using 1,2‐N, O‐carbonyl‐β‐D‐glycopyranoses. Hydrazinocarbonyl‐methyl‐ and ‐propyl spacers also were found appropriate for linking norfloxacin with sugar units. Dedicated to Professor A. Messmer on the occasion of his 80th anniversary.

On treatment with glyoxylic acid and hydrazine hydrate, 1,1′-diacetylferrocene was converted into the separable mixture of 1,1′-bis [pyridazin-3(2H)-one-6-yl]ferrocene and the hydrazone as well as the azine of 1-acetyl-1′-[pyridazin-3(2H)-one-6-yl]ferrocene. Successful cyclizations of 1,1′-bis[pyridazin-3(2H)-one-6-yl]ferrocene resulting in a series of novel ferrocenophanes containing heterocyclic units were performed under phase transfer- and homogeneous catalytic (RCM) conditions by the application of versatile dialkylating agents and second generation Grubbs’ catalyst, respectively. The structures were determined by mass spectrometry, IR, 1H and 13C NMR spectroscopy including 2D-COSY, HMQC and HMBC measurements. The solid phase structure of a dimer product with π-stacking interaction was revealed by X-ray analysis.

t-2-Benzoyl-t-4-phenylcyclohexane-r-1-carboxylic acid reacts with hydrazine to give the saturated 1,7-diphenyl-trans-phthalazin-4(3H)-one. The reaction of the acid with ethylenediamine yields diastereomeric trans-imidazo[2,3-a]isoindoles, which differ in their C-1 configuration. The cyclizations of the acid with cis-2-aminocyclohexane- or 4-cyclohexenemethanol result in trans-isoindolo[2,1-a][3,1]benzoxazines, while in its reactions with the analogous di-endo- and di-exo-norbornane- and -norborneneamino alcohols, the acid gives methylene-bridged isomeric di-endo-norbornanes or a norbornene derivative; the corresponding diastereomeric di-exo derivatives have also been prepared. After isolation, the structures were established by means of 1H and 13C NMR spectroscopy, with application of DIFFNOE, DEPT, HMQC, HMBC, and 2D-COSY techniques.

(Di-exo-3-amino-7-oxabicyclo[2.2.1]hept-5-en-2-yl)methanol (3) was treated with oxo carboxylic acids [p-toluoylpropionic acid, cis- or trans-(p-toluoyl)cyclohexanecarboxylic acid, -benzoic acid or methanobenzocyclooctenecarboxylic acid] to furnish the oxanorbornene-fused pyrrolo[1,3]oxazine 4, the isoindolo[1,3]oxazines 5 and 6, and the methanobenzocyclooctenepyrrolo[1,3]oxazine 10, together with the retro-Diels−Alder products pyrrolooxazinone 7, oxazinoisoindolones 8 and 9, and oxazinopyrrolobenzocyclooctene 11. On reflux in chlorobenzene, furan was released from the oxanorbornene heterocycles 5 and 10 to give the retro-Diels−Alder products. The structures of the new compounds were established by NMR spectroscopy and also (for 6 and 9) by single-crystal X-ray structure determination. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

During the alkaline methanolysis of 3β-acetoxy-21-chloromethyl-pregn-5-ene-20β- N -phenylurethane, and its p -substituted phenyl derivatives, cyclization occurs, in the course of which 17β-[3-( N -phenyl)tetrahydrooxazin-2-on-6-yl]androst-5-en-3β-ol and its p -substituted phenyl derivatives are formed. The cyclization takes place with (N − -6) neighboring group participation. Oppenauer oxidation of the 3β-hydroxy- exo -heterocyclic steroids yielded the corresponding Δ 4 -3-ketosteroids. The structures of the new compounds were proved by IR, 1 H and 13 C NMR spectroscopy, using up-to-date measuring techniques such as 2D-COSY, HMQC, and HMBC. The inhibitory effects (CI 50 ) of the Δ 4 -3-ketosteroids on 5α-reductase were studied.