Chemie angeregter zustände. V. mitt.: photocyclisierung von benzalanthronen

Scholz, M.; Dietz, F.; Mühlstädt, M.

doi:10.1016/s0040-4039(01)98353-4

Cited by 11 publications

(9 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Irradiation of 322 mg of this imine for 67 h in 250 mL of cyclohexane using a 400-watt mercury lamp provided 6-phenylphenanthridine ( 2 ) in 46% isolated yield [ 28 ]. According to the literature [ 31 , 32 , 33 ], the reaction on similar substrates can be accelerated via protonation of starting imine by addition of acid. Indeed, according to GC-MS analysis, a full conversion and promising 35% yield was achieved using 100 mg of 1 in the presence of 4 equivalents of HBF 4 ·Et 2 O within 4 h according to GC-MS analysis.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Oxidative Photocyclization of Aromatic Schiff Bases in Synthesis of Phenanthridines and Other Aza-PAHs

Kos

Žádný

Storch

et al. 2020

IJMS

View full text Add to dashboard Cite

The oxidative photocyclization of aromatic Schiff bases was investigated as a potential method for synthesis of phenanthridine derivatives, biologically active compounds with medical applications. Although it is possible to prepare the desired phenanthridines using such an approach, the reaction has to be performed in the presence of acid and TEMPO to increase reaction rate and yield. The reaction kinetics was studied on a series of substituted imines covering the range from electron-withdrawing to electron-donating substituents. It was found that imines with electron-withdrawing substituents react one order of magnitude faster than imines bearing electron-donating groups. The 1H NMR monitoring of the reaction course showed that a significant part of the Z isomer in the reaction is transformed into E isomer which is more prone to photocyclization. The portion of the Z isomer transformed showed a linear correlation to the Hammett substituent constants. The reaction scope was expanded towards synthesis of larger aromatic systems, namely to the synthesis of strained aromatic systems, e.g., helicenes. In this respect, it was found that the scope of oxidative photocyclization of aromatic imines is limited to the formation of no more than five ortho-fused aromatic rings.

show abstract

Section: Resultsmentioning

confidence: 99%

“…This suggestion is supported by the fact that N -benzylideneaniline [ 30 ] and other imines readily cyclize to the corresponding phenanthridines in the presence of strong acid such as e.g., conc. H 2 SO 4 [ 31 , 32 , 33 ]. In this case, the nitrogen lone pair is protonated and 1 π,π* is the lowest energy state.…”

Section: Introductionmentioning

confidence: 99%

Oxidative Photocyclization of Aromatic Schiff Bases in Synthesis of Phenanthridines and Other Aza-PAHs

Kos

Žádný

Storch

et al. 2020

IJMS

View full text Add to dashboard Cite

show abstract

“…Diphenylmethyleneaminobenzene (OPA1 0 ) was irradiated in a concentrated sulfuric acid (Scheme 1). [14,15] The absorption spectra before and after the irradiation were measured, and the spectra totally changed before and after the experiment as shown in Figure 2. Therefore, OPA1 0 was successfully converted to the corresponding phenanthridine (P1), expected as only one product, through photocyclization…”

Section: Photocyclization Of Opa'smentioning

confidence: 99%

Modification and Electrochemical Properties of Poly(phenylazomethine) Derivatives

Higuchi

Hayashi

Yamamoto

2006

Macromolecular Symposia

View full text Add to dashboard Cite

Summary: Oligo(phenylazomethine)s (OPAs) and aniline-capped OPAs (OPA's) are used as model compounds of polyphenylazomethine (PPA), and their fundamental properties and their modification methods are investigated. Cyclic voltammograms of bis(diphenylmethyleneamino)benzene (OPA2 0 ) showed irreversible redox response in the presence of trifluoroacetic acid. A selective synthesis of oligophenanthridine was achieved through the photocyclization of OPA2 0 in concentrated sulfuric acid. Stepwise complexation behavior in dendritic poly(phenylazomethine)s (DPAs) was supported by the shell-selective reduction of the imines. Using the shell-selective reduction method and the terminal-modification method of the DPAs, the core and terminals of DPAs were functionalized by ferrocene units, respectively.

show abstract

“…Photocyclization OPA1' in a concentrated sulfuric acid was photochemically converted to the corresponding phenanthridine (P1) (Scheme 4(a)) [21,22]. The UV-vis spectra of OPA1' and P1 are shown in Fig.…”

Section: Electrochemical Propertymentioning

confidence: 99%

Oligophenylazomethines: synthesis, structure, electrochemical property and photocyclization

Higuchi

Yamamoto

2002

Polymers for Advanced Techs

View full text Add to dashboard Cite

Oligophenylazomethines (OPAs) and the aniline‐capped OPAs (OPA's) as soluble model compounds of polyphenylazomethine (PPA) were synthesized via dehydration of 4‐aminobenzophenone in the presence of TiCl4 or PTS as a Lewis acid. The 1H‐NMR spectra of OPAs revealed that OPAs have some isomers, which are based on the E/Z conformation of the azomethine moieties, and the formation ratio of the E/Z isomers changes due to the intramolecular steric hindrance of the oligomers. The cyclic voltammograms of OPA's showed irreversible redox waves in the presence of trifluoroacetic acid. Photocyclization of OPA's proceeded in concentrated sulfuric acid. Copyright © 2003 John Wiley & Sons, Ltd.

show abstract

Chemie angeregter zustände. V. mitt.: photocyclisierung von benzalanthronen

Cited by 11 publications

References 8 publications

Oxidative Photocyclization of Aromatic Schiff Bases in Synthesis of Phenanthridines and Other Aza-PAHs

Oxidative Photocyclization of Aromatic Schiff Bases in Synthesis of Phenanthridines and Other Aza-PAHs

Modification and Electrochemical Properties of Poly(phenylazomethine) Derivatives

Oligophenylazomethines: synthesis, structure, electrochemical property and photocyclization

Contact Info

Product

Resources

About