Synthese von Dimethyl‐4a,8a‐methanophthalazin‐1,4‐dicarboxylat und Derivaten

Neidlein, R.; Tadesse, Lema

doi:10.1002/hlca.19880710127

Cited by 19 publications

(4 citation statements)

References 11 publications

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“…Its 1,2 double bond is to a large extent isolated from other π-electron systems, and is unique for its aliphatic character. The other two aromatic bonds (3,4 and 4,5see insert in Table ) can also function as diene in some [4 + 2] cycloadditions. − Recent studies have also shown that the π bonds of the aromatic ring can react as dienophile. , The length of the three double bonds in the acenaphthylene molecule is in the sequence C1−C2 (1.36 Å) < C4−C5 (1.38 Å) < C3−C4 (1.43 Å), and the bond order is reversed, C1−C2 (1.83) > C4−C5 (1.72) > C3−C4 (1.18) (see Table ). The bond order was predicted by using the AIM feature in Gaussian based on the theory of atoms in molecules developed by Bader and co-workers, which defines chemical properties on the basis of the topology of the electron density.…”

Section: Resultsmentioning

confidence: 99%

Radical−Molecule Reactions for Aromatic Growth: A Case Study for Cyclopentadienyl and Acenaphthylene

Wang

Violi²

2006

J. Org. Chem.

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Polycyclic aromatic hydrocarbon growth from acenaphthylene and cyclopentadienyl was investigated by using the B3LYP/6-31G(d,p) and BH&HLYP/6-31G(d,p) levels of theory as well as transition state theory. The reaction pathways of cyclopentadienyl bearing hydrocarbons are different from those without these moieties and cannot be adequately accounted for by the existing acetylene addition and aryl-aryl addition mechanisms. The reaction mechanisms identified in this paper lead to the formation of fluoranthene, aceanthrylene, and acephenanthrylene. Rate constants of the radical-molecule addition and subsequent intramolecular addition steps predict that the 1,2 double bond in acenaphthylene is much more reactive than the 3,4 and 4,5 double bonds. Fluoranthene is the most abundant product produced at high temperatures and the yield of acephenanthrylene is bigger than that of aceanthrylene. The computational results are discussed in light of pyrolysis experiments on CPD-indene and CPD-acenaphthylene mixtures conducted by Prof. Mulholland's research group reported in a previous work.

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Section: Resultsmentioning

confidence: 99%

Radical−Molecule Reactions for Aromatic Growth: A Case Study for Cyclopentadienyl and Acenaphthylene

Wang

Violi²

2006

J. Org. Chem.

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“…Strongly electron deficient triazines, e.g., R 1 -R 3 ) CO 2 Et, add under normal conditions but when less activated, e.g., R 1 ) R 2 ) H; R 3 ) CO 2 Et, highpressure conditions are required. In contrast, the addition of tetrazine dicarboxylate 242 or bis(trifluoromethyl)tetrazine leads to product 212 in the norcaradiene form. Indeed, 212 (R ) CF 3 ) has provided for subsequent significant synthetic chemistry in which the distinct electron-rich cyclohexadiene and electron deficient diazadiene moieties are utilized independently.…”

Section: In Cycloadditionsmentioning

confidence: 99%

“…222 In similar vein, R-pyrone provides methano- [10]annulene after loss of CO 2 . 197 Reactions with triazines 240,241 or tetrazines 242,243 likewise lead to addition-elimination, this time of dinitrogen. Addition of triazine gives a product is which the threemembered ring is opened, viz.…”

Section: In Cycloadditionsmentioning

confidence: 99%

Cycloproparenes

Halton

2003

Chem. Rev.

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“…128.1 (C16l2O), 128.6 (CI7/Ig), 128.8 (C3t6), 129.7 (ClDlt4 or Cl llI3),131.6 (Cl l/13 or c10/14), 13s.5 (c9), 138.7(8) (C2a or C6a), 138.8(1) (C6a or CZa), 139.0 (C15). Mass spectnrm (relative intensity): m/z (70 eV) 385 (16,Cz+FIr58rBr +1), 384 (63, CzallrssrBr), 382(57, Cz+FIrs7eBd,3a4 (10),303 (37, M-Br),302 (100, M-I{Br'),301 (18),300 (47)' 298 (10), l5l (19) r50 (197o).…”

Section: ' -( Phenylpenryiidene)-lh-cyclopropa[b] Naphthalene ( I I4n|mentioning

confidence: 99%

Studies of Some Strained Organic Molecules

Jones¹

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<p>The characterisation of rare examples of C1-substituted cyclopropanaphthalenes has been achieved with silanes (104) and (112) by employing the C1 anion (106). With toluene, N,N-dimethylacetamide, and cyclopropanaphthalene (58) this same anion gives the novel 6-methyl-7H-dibenzo[b,g]fluorene (179), a formal dimer of cycloproparene (58). Hydrocarbon (179) is the sole dibenzo[b,g]hydrocarbon characterised and this has required extensive spectroscopic study with confirmation from X-ray analysis. A possible new route to alkylidenecyclopropanaphthalenes (114) employing lithiate (170) and either cycloproparene (58) or its disilyl analogue (105) was found to offer no advantage over known procedures. Application of the protocols embodied in this procedure to brominated synthons (114o) and (114p) has afforded novel pi-extended methylidene compounds (197a) and (199) in low yield. Cyclopentadienylidene (197a) has also been prepared in better yield from benzophenone-containing methylidenecycloproparene (200). Initial attempts to obtain (200) from anion (193) and N,N-dimethylbenzamide were unsuccessful and gave instead the new phenol (114q). The first acylcycloproparenes (189) and (202) have been obtained in modest yield from anion (103) and N,N-dimethyl-acetamide, and -benzamide. With N,N-dimethyl-carbamoyl chloride anion (103) gives the bis-amide (205). With hydrochloric acid these acylcycloproparenes give rise to 2,3-disubstituted naphthalenes rather than 2-substituted naphthalenes that typically arise from protonation at the aromatic ring. Thermolysis leads to ring expansion and naphthofuran formation. Enolate formation from the 1-acyl-cyclopropanaphthalenes (189) and (202) and anion capture at oxygen affords the first cyclopropanaphthalenylidene enol ethers (219) and (220). 1H-Cyclopropa[b]naphthalene-3,6-dione (154) adds buta-1,3-diene across the enedione Pi-bond to give the tetrahydrocyclopropanthraquinone (160). Enolisation of (160) provides phenolate (234) that can be diverted to ether (229) or oxidised to the dihydroanthraquinone (230). Dehydrogenation of (229) is readily achieved and gives the first anthraquinone of the cycloproparene series 1H-cyclopropa[b]anthracene-3,8-dione (162); quinone (162) is only the second cyclopropaquinone to have been characterised. Alternative routes to quinone (162) and its 3,8-dimethoxy analogue (163) have been examined with a view to providing the first alkylidenecyclopropanthracenes. The first examples of cross-conjugated dithiole-containing cycloproparenes, (169) and (267), have been prepared from cyclopropanthraquinone (162) but they are unstable solids. The pi-extended dithiole-containing methylidene compound (273) has been prepared in good yield from Wittig-Horner olefination of the benzoylmethylidene compound (200). Evidence was obtained to support the formation of a charge-transfer complex from it. Ketones already carrying a conjugated dithiole moiety participate in the Peterson olefination with the alpha-silyl anion (106) and give the new pi-extended methylidenecyclopropanaphthalenes (274) and (277) of limited stability.</p>

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Synthese von Dimethyl‐4a,8a‐methanophthalazin‐1,4‐dicarboxylat und Derivaten

Cited by 19 publications

References 11 publications

Radical−Molecule Reactions for Aromatic Growth: A Case Study for Cyclopentadienyl and Acenaphthylene

Radical−Molecule Reactions for Aromatic Growth: A Case Study for Cyclopentadienyl and Acenaphthylene

Cycloproparenes

Studies of Some Strained Organic Molecules

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