- The Anisotropic Effect of 4-Subsituents on the 1H NMR Chemical Shift of H-5 in Phenantrenes
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Chloro-, methoxy- and methyl-substituents in the 4-position of phenantrenes exert a profound and diagnostic influence on the 1H chemical shift of H-5, and from 13C measurments it is considered to be due to an anisotropic effect.
- Letcher, R. M.
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- Regioselective arene homologation through rhenium-catalyzed deoxygenative aromatization of 7-oxabicyclo[2.2.1]hepta-2,5-dienes
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Combined use of oxorhenium catalysts with triphenyl phosphite as an oxygen acceptor allowed efficient deoxygenative aromatization of oxabicyclic dienes. The reaction proceeded under neutral conditions and was compatible with various functional groups. Combining this deoxygenation with regioselective bromination and trapping of the generated aryne with furan resulted in benzannulative π-extension at the periphery of the PAHs. This enabled direct use of unfunctionalized PAHs for extension of π-conjugation. Iteration of the transformations increased the number of fused-benzene rings one at a time, which has the potential to alter the properties of PAHs by fine-tuning the degree of π-conjugation, shape, and edge topology.
- Murai, Masahito,Ogita, Takuya,Takai, Kazuhiko
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p. 2332 - 2335
(2019/02/27)
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- Straightforward synthesis of phenanthrenes from styrenes and arenes
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Semi-one-pot synthesis of phenanthrenes from styrenes and arenes was developed through cross-dehydrogenative coupling. A sequence of Heck-type coupling and photo-cyclization were involved and a variety of functionalities were tolerated. This method provides an effective and practical protocol towards the synthesis of substituted phenanthrenes. The Royal Society of Chemistry 2012.
- Li, Hu,He, Ke-Han,Liu, Jia,Wang, Bi-Qin,Zhao, Ke-Qing,Hu, Ping,Shi, Zhang-Jie
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p. 7028 - 7030
(2012/08/07)
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- α-Oxoketene dithioacetal mediated aromatic annulation: Highly efficient and concise synthetic routes to potentially carcinogenic polycyclic aromatic hydrocarbons
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Highly efficient regiospecific routes to potentially carcinogenic polycyclic aromatic hydrocarbons such as substituted benzo[c]phenanthrenes, benzo[c]fluorenes, 16,17-dihydro-11-methyl-15[H]cyclopenta[a]phenanthrene, 5-methyl-7,8,9,10-tetrahydrochrysene and 1,4-dimethylphenanthrene have been developed. The overall strategy involves our aromatic annulation protocol through base induced conjugate addition-elimination on the cyclic and acyclic α-oxoketene dithioacetals with the appropriate arylacetonitriles followed by acid induced cyclodehydration of the resulting conjugate adducts. Subsequent reductive dethiomethylation (Raney Ni) and dehydrogenation (DDQ) of the cyclized products affords the methyl substituted PAHs in high yields.
- Nandi, Sukumar,Panda, Kausik,Suresh,Ila, Hiriyakkanavar,Junjappa, Hiriyakkanavar
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p. 3663 - 3673
(2007/10/03)
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