95690-49-6Relevant academic research and scientific papers
Modular, Metal-Catalyzed Cycloisomerization Approach to Angularly Fused Polycyclic Aromatic Hydrocarbons and Their Oxidized Derivatives
Thomson, Paul F.,Parrish, Damon,Pradhan, Padmanava,Lakshman, Mahesh K.
, p. 7435 - 7446 (2015/08/18)
Palladium-catalyzed cross-coupling reactions of 2-bromobenzaldehyde and 6-bromo-2,3-dimethoxybenzaldehyde with 4-methyl-1-naphthaleneboronic acid and acenaphthene-5-boronic acid gave corresponding o-naphthyl benzaldehydes. Corey-Fuchs olefination followed by reaction with n-BuLi led to various 1-(2-ethynylphenyl)naphthalenes. Cycloisomerization of individual 1-(2-ethynylphenyl)naphthalenes to various benzo[c]phenanthrene (BcPh) analogues was accomplished smoothly with catalytic PtCl2 in PhMe. In the case of 4,5-dihydrobenzo[l]acephenanthrylene, oxidation with DDQ gave benzo[l]acephenanthrylene. The dimethoxy-substituted benzo[c]phenanthrenes were demethylated with BBr3 and oxidized to the o-quinones with PDC. Reduction of these quinones with NaBH4 in THF/EtOH in an oxygen atmosphere gave the respective dihydrodiols. Exposure of the dihydrodiols to N-bromoacetamide in THF-H2O led to bromohydrins that were cyclized with Amberlite IRA 400 HO- to yield the series 1 diol epoxides. Epoxidation of the dihydrodiols with mCPBA gave the isomeric series 2 diol epoxides. All of the hydrocarbons as well as the methoxy-substituted ones were crystallized and analyzed by X-ray crystallography, and these data are compared to other previously studied BcPh derivatives. The methodology described is highly modular and can be utilized for the synthesis of a wide variety of angularly fused polycyclic aromatic hydrocarbons and their putative metabolites and/or other derivatives.
High temperature gas phase syntheses of C20H12 cyclopenta-fused polycyclic aromatic hydrocarbons: Benz[l]acephenanthrylene and benz[j]acephenanthrylene and their selective rearrangement to benzo[j]fluoranthene
Sarobe, Martin,Jenneskens, Leonardus W.,Wesseling, Jolanda,Wiersum, Ulfert E.
, p. 703 - 708 (2007/10/03)
The novel C20H12 cyclopenta-fused polycyclic aromatic hydrocarbon benz[l]acephenanthrylene (2) and its isomer benz[j]acephenanthrylene (3) have been obtained by flash vacuum thermolysis of 2-(1-chloroethenyl)benzo[c]phenanthrene (6) and 6-(1-chloroethenyl)chrysene (7), respectively. At T ≥ 900°C 2 and T ≥ 1000°C 3 rearrange selectively to the abundant combustion effluent benzo[j]-fluoranthene (1). No evidence for the presence of the related rearrangement products benz[l]aceanthrylene (12) and benz[j]aceanthrylene (13), respectively, is found. Semi-empirical AM1 calculations provide a rationalization for these observations; the conversion of 2 and 3 into 1, instead of 12 and 13, respectively, via consecutive ring-contraction-ring-expansion processes and vice versa is favoured.
