Synthesen und Eigenschaften ethinylierter und trimethylsilylethinylierter Molekülsysteme mit 1,6-Methano[10]annulen-Partialstruktur

2-Trimethylsilylethinylated 1,6-methano[10]annulene1 a was obtained by reaction of 2-bromo-1,6-methano[10]annulene with trimethylsilylacetylene in the presence of bis-(triphenylphosphin-)-Pd (II) chloride and Cu(I) and also by reaction of 1,1-diiodo-2-(1,6-methano[10]annulene-2-yl)-ethene (2) withn-buthyl-lithium followed by hydrolysis.1 a reacts with 2N NaOH to 2-ethinyl-1,6-methano[10]annulene (1 b). 2,7- and 2,10-dibromo-1,6-methano[10]annulene can be substituted to give the trimethylsilylethinylated compounds3 a–6 a, which then can be transformed with 2N NaOH into the desilylated products3 b–5 b.

Wolfgang Kraus, Stuttgart-Hohenheim, mit den besten Wünschen in Freundschaft zum 60. Geburtstag gewidmet     

On triazoles. X. The reaction of 5-amino-1,2,4-triazoles with tetrahydrothiophene β-keto esters

Three novel ring systems, namely the thieno[3,4-d]-1,2,4-triazolo[1,5-a]pyrimidine, the thieno[3,4-e]-1,2,4-triazolo[1,5-a]pyrimidine and the thieno[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidine were synthesised. The structure of compounds obtained was proved with the help of their uv and cmr spectra using model compounds prepared for this purpose.     

Mechanistic and Synthetic Studies on the Formation of 1,2,4-Trioxanes Related to Arteannuin. Photooxygenation of a bicyclic dihydropyran

The photooxygenation of (4R,4aS,7R)-4,4a,5,6,7,8-hexahydro-4,7-dimethyl-3H-2-benzopyran ( 16 ) was performed in (i) MeOH, (ii) acetaldehyde, and (iii) acetone at ?78°. The products obtained respectively were (i) (2R)-2-[(1S,4R)-4-methyl-2-oxocyclohexyl]propyl formate ( 17 ; 72% yield), (ii) 17 (54.5%), (1R,4R,4aS,7R)-3,4,4a,5,6,7-hexahydro-4,7-dimethyl-1H-2-benzopyran-2-yl hydroperoxide ( 19 ; 16.7%), a 12:1 ratio of (3R,4aR,7R,7aS,10R,11aR)-7,7a,8,9,10,11-hexahydro-3,7,10-trimethyl-6H-[2]benzopyrano[1,8a-e]-1,2,4-trioxane ( 20 ) and its C(3)-epimer 21 (17%), together with evidence for the 1,2-dioxetane ( 22 ) originating from the addition of dioxygen to the re-re face of the double bond of 16 , and iii) unidentified products and traces of 22 . Addition of trimethylsilyl trifluoromethanesulfonate (Me₃SiOTf) to the acetone solution of 16 after photooxygenation afforded (4aR,7R,7aS,10R,11aR)-7,7a,8,9,10,11-hexahydro-3,3,7,10-tetramethyl-6H-[2]benzopyrano[1,8a-e]-1,2,4,-trioxane ( 23 , 40%). The photooxygenation of 16 in CH₂Cl₂ at ?78° followed by addition of acetone and Me₃SiOTf afforded 17 (11%), 23 (59%), and (4aR,7R,7aS,10R,11aR)-7,7a,8,9,10,11-hexahydro-3,3,7,10-tetramethyl-6H-[2]benzopyrano[8a,1-e]-1,2,4-trioxane ( 24 ; 5%. Repetition of the last experiment, but replacing acetone by cyclopentanone, gave 17 (16%), (4′aR,7′R,7′aS,10′R,11′aR)-7′,7′a,8′,9′,10′,11′-hexahydro-7′,10′-dimethylspiro[cyclopentane-1,3′-6′H-[2]benzopyrano[1,8a-e]-1,2,4-trixane] ( 25 ; 61%), and (4′aR,7′R,7′aS,10′R,11′aR)-7′,7′a,8′,9′,10′,11′-hexahydro-7′,10′-dimethylspiro[cyclopentane-1,3′-6′H-[2]benzopyrano[8a,1-e]-1,2,4-trixane] ( 26 , 4%). The X-ray analysis of 23 was performed, which together with the NMR data, established the structure of the trioxanes 20, 21, 24, 25 , and 26 . Mechanistic and synthesis aspects of these reactions were discussed in relation to the construction of the 1,2,4-trioxane ring in arteannuin and similar molecules.     

On triazoles. XVII . The reaction of 5-amino-1,2,4-triazoles with N-heterocyclic β-oxo-esters

Pyrrolo[3,4-d]-1,2,4-triazolo[1,5-a]pyrimidinone ( 3d ), pyrido[3,4-d]-1,2,4-triazolo[1,5-a]pyrimidinone ( 3e ) and pyrido[4,3-e]-1,2,4-triazolo[1,5-a]pyrimidinone ( 4e ) derivatives representing three new ring systems were synthesised. Their structure was proved by comparing their uv and cmr spectra with those of the known benzo- and thieno-1,2,4-triazolo[1,5-a]pyrimidinones used as model compounds.     

New approaches to synthesis of tris[1,2,4]triazolo[1,3,5]triazines

Thermal cyclization of 3-R-5-chloro-1,2,4-triazoles (R = Cl, Ph) afforded 2,6,10-tri-R- tris[1,2,4]triazolo[1,5-a:1′,5′c:1″,5″-e][1,3,5]triazines 5 (R = Ph) and 7 (R = Cl). These compounds are first representatives of this class of heterocycles, whose structures were unambiguously established. Treatment of these compounds with nucleophiles (H₂O/NaOH, NH₃) results in the triazine ring opening to give compounds consisting of three 1,2,4-triazole rings linked in a chain. For example, treatment of cyclic compound 5 with aqueous alkali affords 3-phenyl-1-3-phenyl-1-(3-phenyl-1H-1,2,4-triazol-5-yl)-1,2,4-triazol-5-yl-1H-1,2,4-triazol-5-one. Treatment of 3,7,11-triphenyltris[1,2,4]triazolo[4,3-a:4′,3′c:4″,3″-e][1,3,5]triazine (2) with HCl/SbCl₅ leads to the triazine ring opening giving rise to 5-(3-chloro-5-phenyl-1,2,4-triazol-4-yl)-3-phenyl-4-(5-phenyl-1H-1,2,4-triazol-3-yl)-1,2,4-triazole. Thermal cyclization of the latter produces 3,7,10-triphenyltris[1,2,4]triazolo[1,5-a:4′,3′c:4″,3″-e][1,3,5]triazine (13). Thermolysis of both cyclic compound 2 and cyclic compound 13 is accompanied by the Dimroth rearrangement to yield 3,6,10-triphenyl-tris[1,2,4]triazolo[1,5-a:1′, 5′-c:4″,3″-e][1,3,5]triazine (14). Compounds 13 and 14 are the first representatives of cyclic compounds with this skeleton. ¹³C NMR spectroscopy allows the determination of the isomer type in a series of tris[1,2,4]triazolo[1,3,5]triazines.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 706–712, March, 2005.     

2,5-Chinonmethide des 1,6-Methano[10]annulens mit S,N- und N,N-Acylketenacetal Struktur

2,5-Quinonemethides of 1,6-Methano[10]annulene with the Structures of S,N- and N,N-Acylketene Acetals Investigation on the chemical reactivities of 2-(tert -butoxy)-1,6-methano[10]annulene and the syntheses of the compounds 2, 4, 6–8, 11, 13–22 are described; the results of ¹H- and ¹³C-NMR-spectroscopic measurements are reported.     

Mass spectrometry of aryl substituted di- and trisiloxanes

The mass spectra of arylpentamethyldisiloxanes, sym-diaryltetramethyldisiloxanes and 1,5-diaryl-1,1,3,3,5,5-hexamethyltrisiloxanes were examined. Isotopic labeling and peak matching were used to substantiate the proposed fragmentation mechanisms. Siliconium ions dominate the spectra. Loss of neutral fragments from the [M-15]⁺ ions is important. Phenylpentamethyldisiloxane, sym-tetramethyldiphenyldisiloxane and 1,1,3,3,5,5-hexamethyl-1,5-diphenyltrisiloxane are representative examples of the three classes of compounds discussed. The [M-15]⁺ ion of phenylpentamethyldisiloxane loses methane, dimethylsilanone [(CH₃)₂Si?O] and phenylmethylsilanone [PhCH₃Si?O] to yield daughter siliconium ions. The [M-15]⁺ ion of sym-tetramethyldiphenyldisiloxane loses benzene, methane, dimethylsilanone and phenylmethylsilanone to yield daughter siliconium ions. The [M-15]⁺ ion of 1,1,3,3,5,5-hexamethyl-1,5-diphenyltrisiloxane loses benzene, tetramethylcyclodisiloxane and phenyltrimethylcyclodisiloxane to yield daughter siliconium ions. Finally, doubly charged ions are important in the mass spectra of the three series of aryl substituted di- and trisiloxanes discussed.     

Perimeter-Type Structures in Charged [4n + 2] Annuleno [4n + 2] annulenes. The Importance of the Frontier-Orbitals

The tetra(tert-butyl)[14]annuleno[14]annulene 1 is transformed, via alkali metal reduction, into its radical monoanion, dianion, radical trianion, and tetraanion. The paramagnetic species are characterized by ESR and ENDOR spectroscopy and the diamagnetic species by ¹H- and ¹³C-NMR spectroscopy. Well-resolved ESR and NMR spectra can only be obtained, if the reduction is carefully monitored. For the interpretation of the data, the ions derived from the structurally related [14]- and [22]annulenes 3 and 5 as well from the tetra(tert-butyl)[14]annuleno[18]annulene 2 serve as suitable model compounds. While the behavior of the neutral annulenoannulene 1 is governed by that of the [14]annulene-subunit, the corresponding ionic systems can best be described as macrocyclic perimeters. This outcome can be rationalized by the nodal properties of the frontier MO's.     

Reduktion von 1,2-bis[(Z)-(2-nitrophenyl)-NNO-azoxy]benzol: Synthese von Cyclotrisazobenzol ( = (5E,6aZ,11E,12aZ,17E,18aZ)-5,6,11,12,17,18-Hexaazatribenzo[aei][1,3,5,7,9,11]cyclododeca-hexaen)

Reduction of 1,2-Bis[(Z)-(2-nitrophenyl)-NNO-azoxy]benzene¹: Synthesis of Cyclotrisazobenzene ( = (5E,6aZ,11E,12aZ,17E,18aZ)-5,6,11,12,17,18-Hexaazatribenzo[aei][1,3,5,7,9,11]cyclododeca-hexaene) Na₂S reduction of 1,2-bis[(Z)-(2-nitrophenyl)-NNO-azoxy]benzene ( 2 ) yielded 3 deoxygenated products: the (known) red 2,2′-((E,E)-1,2-phenylenbisazo)dianiline ( 3 , 23%), the orange 2-[2-((E)-2-aminophenylazo)phenyl]-2H-benzotriazol ( 4 , 55%) and the colorless 2,2′-(1,2-phenylene)di-2H-benzotriazol ( 5 , 13%). The constitutions of 3 – 5 and of 6 , the N-acetyl derivative of 4 , were deduced from their ¹H-NMR spectra (chemical shifts, couplings, and symmetry properties), and the configurations of 3 , 4 , and 6 at their N,N-double bonds are assumed to be the same as in 2 . Oxidation of 3 with 2 mol-equiv. of Pb(OAc)₄ afforded 5 (47%) and a novel, highly symmetrical macrocycle, called cyclotrisazobenzene ( 7 , 24%). The constitution of 7 as a tribenzo-hexaaza[12]annulene and its (E)-configuration at the N,N-bonds was confirmed by X-ray analysis. The molecular symmetry expressed by the ¹H-, ¹³C- and ¹⁵N-NMR spectra of 7 reveals a rapid torsional motion around the six N,C bonds. This implies that the N,N-double bonds in the cyclic 12π-electron system (or 24π-electron system if the benzene rings are included) of 7 are highly localized.     

Infrared spectroscopic detection of sulphone groups in doped polybenzo[c]thiophenes

By reaction of 1,3-dihydrobenzo[c]thiophene with FeCl₃, air or TCNQ the oxidatively doped polybenzo[c]thiophenes (1a, b, d, e) were prepared. Their infrared spectra showed two strong absorptions in the ranges 1265–1337 cm⁻¹ and 1142–1184 cm⁻¹. Efficient drying did not change these absorptions but reaction of 1a, b, d, e with LiAlH₄ resulted in their decrease to weak bands. According to these results and by comparison with the infrared spectra of reference compounds data, 1a—e were found to contain sulphone groups.     

‘Oligomere' Kondensationsprodukte von (1E,3E,5E)‐1,6‐Di(2‐furyl)hexa‐1,3,5‐trien mit Acetaldehyd: Tetrahydro‐tetramethyl‐octaepoxy[60]annulen(6.1.6.1.6.1.6.1)

Oligomeric Condensation Products of (1 E ,3 E ,5 E )‐1,6‐Di(2‐furyl)hexa‐1,3,5‐triene with Acetaldehyde: Tetrahydro‐tetramethyl‐octaepoxy[60]annulene(6.1.6.1.6.1.6.1) The Ca(NO₃)₂‐induced condensation of (1E,3E,5E)‐1,6‐di(2‐furyl)hexa‐1,3,5‐triene ( 6 ) with acetaldehyde yields the linear ‘oligomers' 7 – 11 with 2–6 1,6‐di(2‐furyl)hexa‐1,3,5‐triene units and 1–4 acetaldehyde units, besides a cyclic condensation product 12 obtained from 4 equiv. of 6 with 4 equiv. of acetaldehyde. According to spectroscopic studies, 12 is the tetrahydro‐tetramethyl‐octaepoxy[60]annulene(6.1.6.1.6.1.6.1) as the most expanded annulene system known so far. While the dehydrogenation of 12 to give the tetramethyl‐octaepoxy[60]annulene(6.1.6.1.6.1.6.1) cannot be achieved, the oxidation of 12 with Br₂ yields a black, in all organic solvents nearly insoluble solid 14 , which possibly is the tetramethyl‐octaepoxy[58]annulene(6.1.6.1.6.1.6.1) dication. Because of the insolubility of 14 , unfortunately most of its spectroscopic data are not available. However, the λ_max values in the UV/VIS/NIR spectrum of 14 (Soret and Q bands) are in line with the values of the tetraepoxy[26]annulene(4.2.4.2) dication, the tetraepoxy[30]annulene(4.4.4.4) dication, and the tetraepoxy[34]annulene(6.4.6.4) dication.     

On triazoles XXIV . Synthesis of cycloalka[1,2,4]triazolo[1,5-a]pyrimidinones

The uv and nmr spectral data of some 6,7,8,9,10,11-hexahydrocyclohepta[d][1,2,4]triazolo[1,5-a]pyrimidin-5-one, 5,6,7,8,9,11-hexahydrocyclohepta[e][1,2,4]triazolo[1,5-a]pyrimidin-10-one, 6,7,8,9,10,11-hexahydrocycloocta[d][1,2,4]triazolo[1,5-a]pyrimidin-5(12H)-one, 5,6,7,8,9,10-hexahydrocycloocta[e][1,2,4]triazolo[1,5-a]-pyrimidin-11(12H)-one, 6,7,8,9,10,11,12,13,14,15-decahydrocyclododeca[d][1,2,4]triazolo[1,5-a]pyrimidin-5(16H)-one and 5,6,7,8,9,10,11,12,13,14-decahydrocyclododeca[e][1,2,4]triazolo[1,5-a]pyrimidin-15(16H)-one as well as their N-benzylated derivatives representing six novel ring systems were compared to prove their structure. The N-benzylation of the highly insoluble cyclic amides to yield the isomeric N-benzyl derivatives 3/1, 3/2 and 3/3 distinguished by INAPT was performed through their readily soluble tetrabutylammonium salts.     

Quinazolincs and 1,4-benzodiazepines. LXXXVI. The synthesis of imidazothienodiazepines and imidazopyrazolodiazepines

The thieno[3,2-e][1,4]diazepin-2-one ( 1a ), the thieno[2,3-e] [ 1,4] diazepin-2-one ( 1b ), the pyrazolo[3,4-e][1,4]diazepin-2-one ( 1c ) and a chloro analog of 1b , compound 1d , were each converted to derivatives of the novel tricyclic ring systems 4H-imidazo[1,5-a]thieno[2,3-f] [1,4]-diazepine, 4Himidazo[1,5a]thieno[2,3f][1,4]diazepine and 4H-imidazo[ 1,5-a]pyrazolo[4,3-f]-[1,4]diazepine. Depending on the substituents desired on the imidazo ring, two different synthetic pathways were employed.     

Electron impact mass spectrometry of isomeric [(5-N-methyl) and (12-N-methyl)]-11-(o- and p-R-aniline)-5H-dibenzo [b,e] [1,4]diazepines

The mass spectra of twelve isomeric [(5-N-methyl) and (12-N-methyl)]-11-(o- and p-R-aniline)-5H-dibenzo [b, e] [l,4]diazepines which have potentially useful pharmacological properties are presented.     

Synthesis of [1]benzothieno[2,3-e]pyrrolo[1,2a]pyrazines and related compounds

The synthesis of several [1]benzothieno[2,3-e]pyrrolo[1,2-a]pyrazines and other related heterocycles has been described. A study of the nmr spectra of these compounds was also reported.     

Reactions of 3-alkylsulfanyl-2-arylazo-3-(1-azacycloalk-1-yl)acrylonitriles with maleimide

Reactions of 2-arylazo-3-(1-azacycloalk-1-yl)-3-methylsulfanylacrylonitriles with male-imide in benzene gave octahydropyrrolo[3,4-a]pyrrolizines 2a–c, decahydro-2,7a-diaza-cyclopenta[a]indene 2e, and decahydro-5-oxa-2,7a-diazacyclopenta[a]indene 2f as a result of 1,3-dipolar cycloaddition. In a similar reaction with 3-allylsulfanyl-2-arylazo-3-(1-azacycloalk-1-yl)acrylonitriles 3, dipolar cycloaddition and intramolecular cyclization competed to give a mixture of compounds 2 (major products) and 1,4,6,7,8,8a-hexahydropyrrolo[2,1-c]-1,2,4-triazines 4b–d, 1,6,7,8,9,9a-hexahydro-4H-pyrido[2,1-c]-1,2,4-triazine 4e, and 1,4,6,7,9,9a-hexahydro-1,4-oxazino[3,4-c]-1,2,4-triazine 4f (minor products).     

Über die Reaktionen von Guanidin bzw. Harnstoff mit Aminonitrilen

The aminonitriles3a–f react with guanidine inDMF to yield the 5,5-resp. 5-subtituted imidazolidine-2,4-diimines2a–d resp.2f, whereas2e could not be isolated. 7,14-diazadispiro[5.1.5.2]-pentadecan-15-on (7)¹, 4-imino-1,3-diazaspiro[4.5]decan-2-one (8a)¹ and the 2,4-diaminotriazine (9)¹ were isolated as byproducts.1-Aminocyclohexancarbonitrile (3a) reacts with urea to the 4-imino-1,3-diazaspiro[4.5]decan-2-one (8a)¹;8a can be prepared from (1-cyancyclohexyl)urea (11a) as well. The structures of the new compounds are proved by NMR-, IR- and mass spectra and the mechanism of the reaction is discussed.

Herrn Prof. Dr.G. Zigeuner zum 60. Geburtstag gewidmet.     

Novel polycyclic heterocycles. VII. Synthesis of tetracyclic ketones and derivatives from tricyclic 5,11-dihydrodibenz[b,e][1,4] oxazepines

Michael addition of 5,11-dihydrodibenz[b,e][1,4]oxazepines to acrylonitrile gave 5,11-di-hydrodibenz[b,e][1,4]oxazepine-5-propionitriles, which were converted to the corresponding methyl 5-propionates. Mild alkaline hydrolysis of these esters furnished the key intermediates, the 5,11-dihydrodibenz[b,e] [1,4]oxazepine-5-propionic acids. In the preferred procedure, these propionic acids were cyclized to the tetracyclic ketones in yields of 60-90%, by the action of one equivalent of trifluoroacetic anhydride in benzene. When ring C was involved in cylcization, 1,2-dihydro-3H,7H-quino[8,1-cd][1,5]benzoxazepin-3-ones were obtained, and when ring A was involved, 1,2-dihydro-3H,8H-quino[1,8-ab] [4,1]benzoxazepin-3-ones were formed. With 1c , both modes of cyclization were observed. In an alternative procedure that gave lower yields, the propionic acids were first converted to the corresponding acid chlorides, and these were cyclized by means of anhydrous stannic chloride; as anticipated, the products by this method were identical with those obtained via the trifluoroacetic anhydride method. Several reactions of these tetra-cylcic ketones, e.g., their ease of oxime formation, and dehydrogenation to the α,β-unsaturated ketones, are described. The α,β-unsaturated ketones do not form oximes. The structures assigned to the ketones are based on interpretations of their pmr, uv, and ir spectra. These assignments were confirmed by an X-ray analysis of a single crystal of one representative ketone, 2b ; the X-ray study was also useful in indicating the thermodynamically preferred conformation of 2b . The structures of all the other compounds followed from similar spectral interpretations. The mass spectra of a few compounds are also discussed.     

New polyheterocyclic series based on 4,5,6,7-tetrahydrothieno[2,3-c]pyridine

4,8-Dimethyl-6,7,8,9-tetrahydropyrido[4′,3′:4,5]thieno[2,3-e][1,2,4]triazolo[3,4-a]-4H-pyrimidin-5-ones, 7-methyl-2,3,6,7,8,9-hexahydropyrido[4′,3′:4,5]thieno[2,3-d]pyrrolo[1,2-a]-1H, 10H-pyrimidin-10-one, 8-methyl-1,2,3,4,7,8,9,10-octahydropyrido[4′,3′:4,5]thieno[2,3-d]-11H-pyrimidin-11-one, and 9-methyl-2,3,4,5,8,9,10,11-octahydro[4′,3′:4,5]thieno[2,3-d]azepino-[1,2-a]-1H, 12H-pyrimidin-12-one which consist four new heterocyclic ring systems were synthesized from 2-amino-3-carbethoxy-5-methyl-4,5,6,7-tetrahydrothieno[2,3-c]pyridine.     

Strain‐Promoted Double Azide Addition to Octadehydrodibenzo[12]annulene Derivatives

Octadehydrodibenzo[12]annulenes (DBAs), readily available by the oxidative acetylenic coupling of 1,2‐diethynylbenzene derivatives, were reacted with organic azides. As compared to the well‐known strain‐promoted azide‐alkyne cycloaddition (SpAAC) of 5,6,11,12‐tetradehydrodibenzo[a,e][8]annulene, the reactivity of the DBA alkynes was lower due to the lower strain energy. However, the regioselective double azide addition occurred without any side reactions under mild conditions, yielding bis‐triazole products. The structures of the products were confirmed by an X‐ray crystal structure analysis, and the reaction mechanism was studied by ¹H‐NMR spectroscopy and computational studies. It was also found that the DBAs were hardly fluorescent, while the bis‐triazole products showed a green fluorescence with quantum yields up to 5.1 %. Finally, the new strain‐promoted double azide addition to the DBAs was used for step‐growth polymerization, successfully producing a high molecular weight triazole polymer.