- Rapid and convergent assembly of natural benzo[c]phenanthridines by palladium/norbornene catalysis
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A straightforward total synthesis of a small panel of natural benzo[c]phenanthridines is described. The selective coupling of an aryl triflate with a bromobenzylamine by means of palladium/norbornene joint catalysis and a sequential transfer hydrogenation
- Deyris, Pierre-Alexandre,Caneque-Cobo, Tatiana,Gomes, Filipe,Narbonne, Vanessa,Maestri, Giovanni,Malacria, Max
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- A Short Total Synthesis of Benzophenanthridine Alkaloids via a Rhodium(III)-Catalyzed C-H Ring-Opening Reaction
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The biologically important naturally available benzophenanthridines were prepared efficiently in three steps with overall good yields. A new synthetic methodology involving a rhodium(III) catalyzed redox-neutral ring-opening of 7-azabenzonorbornadienes with aromatic aldoximes is developed to synthesize the target molecules. The developed C-H ring-opening reaction is highly diastereoselective and compatible with various sensitive functional group substituted aromatic aldoximes as well as substituted 7-azabenzonorbornadienes. The ring-opening products were transformed into highly sensitive 13,14-dehydrobenzo phenanthridine derivatives by HCl hydrolysis. Subsequently, 13,14-dehydrobenzophenanthridines were converted into biologically important benzophenanthridine alkaloids in the presence of DDQ. A possible reaction mechanism was proposed for the C-H ring-opening reaction and supported by the deuterium labeling studies.
- Aravindan, Narasingan,Jeganmohan, Masilamani
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p. 14826 - 14843
(2021/10/20)
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- (Z)-Ethyl 2-phenyl-1-(2-vinylphenyl)vinylcarbamates. Part 1: Synthesis and preliminary studies on their divergent transformation into benzo[c] phenanthridines and 2-phenyl-1,4-naphthoquinones
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Treatment of N-carbethoxy-1-benzylideneisoquinolines with LDA gives N-ethoxycarbonyl-1-amino-1-(2-vinylphenyl)-2-phenylethylenes, which can easily be transformed into N-carbethoxy-1-amino-2-phenylnaphthalenes. Bischler-Napieralski reaction of these latter
- Treus, Mónica,Salas, Cristian O.,Gonazález, Marcos A.,Estévez, Juan C.,Tapia, Ricardo A.,Estévez, Ramón J.
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experimental part
p. 9986 - 9995
(2011/02/23)
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- BENZOPHENANTHRIDES. XV. SYNTHESIS OF O-METHYLFAGARONINE IODIDE AND CHLORIDE FROM 13α-HYDROXYXYLOPININE
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Hydroborination of 3-(2-vinyl-4,5-dimethoxyphenyl)-6,7-dimethoxy-2-methyl-1,2-dihydro-1-isoquinolone gave 3--6,7-dimethoxy-2-methylisoquinolin-1-one, which was converted by the action of various oxidizing agents into a benzophenanthridone derivative. 5-Methyl-5,6-dihydro-2,3,8,9-tetramethoxybenzophenanthridine, obtained from the above benzophenanthridone by reduction with LiAlH4 in tetrahydrofuran at 0 deg C, was converted into O-methylfagaronine iodide by boiling in an ethanolic solution of I2 in the presence of Na acetate.On exchanging I- by Cl-, O-methylfagaronine chloride was obtained in a quantitative yield in boiling methanol with an excess of AgCl.
- Sazonova, N. M.,Levina, I. I.,Sladkov, V. I.,Suvorov, N. N.
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p. 1751 - 1756
(2007/10/02)
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- A Very Short Route to Fully Aromatic 2,3,8,9- and 2,3,8,9,12-Oxygenated Benzophenanthridines
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Cyclisation of suitably substituted 2-benzylamino-2-phenylacetonitriles proceeds by rearrangement in sulphuric acid or anhydrous hydrogen fluoride, to give 3-aryl-1,2-dihydroisoquinolinones possessing all but two carbons of the benzophenanthridine ring system.These two carbon atoms are introduced in high yield by means of a modified Reformatski reaction and the resulting ester is cyclised in sulphuric acid, with concomitant dehydration and oxidation, to give the fully aromatic four-ring system in only four steps.
- Olugbade, Tiwalade A.,Waigh, Roger D.,Mackay, Simon P.
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p. 2657 - 2660
(2007/10/02)
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- Direct Synthesis of Benzophenanthridines and Benzophenanthridones via SRN1 Reactions
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A straightforward and high-yield route to the 11,12-dihydrobenzophenanthridine (3) and 11,12-dihydrobenzophenanthridone (14) ring systems is based upon an SRN1 reaction between 2-halobenzylamines 1 or 2-halobenzoic acids 11 and enolates derived from tetralones 2.The efficient dehydrogenation of 3 or 14 gives the benzophenthridines 4 or benzophenanthridones 15.Use of properly substituted reactants leads to nitidine, avicine, and fagaronine and to analogues of those natural products.
- Beugelmans, Rene,Chastanet, Jacqueline,Ginsburg, Helene,Quintero-Cortes, Leticia,Roussi, Georges
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p. 4933 - 4938
(2007/10/02)
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- Synthesis and biological activity of some antitumor benzophenanthridinium salts
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A facile synthesis of benzophenanthridinium salts was developed and used for preparing a number of these compounds. The antitumor activities in mouse leukemia L1210 (LE) and P388 (PS) were determined as well as some selected antimicrobial activities. Alth
- Stermitz,Gillespie,Amoros,Romero,Stermitz,Larson,Earl,Ogg
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p. 708 - 713
(2007/10/05)
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