- Synthesis of 1,2-Dihydroisoquinolines by a Modified Pomeranz-Fritsch Cyclization
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Isoquinolines (IQs) and their derivatives are present in many natural products and biologically active small molecules. Herein, we report a modified procedure for the classical Pomeranz-Fritsch protocol, which expands the scope of 1,2-dihydroisoquinoline (DHIQ) products. 1,2-DHIQs are an attractive branch point for the synthesis of IQs, but because of their innate reactivity, they have remained difficult to prepare. We demonstrate that the Fujioka/Kita conditions, combining trimethylsiyltriflate (TMSOTf) and an amine base, activate dimethylacetals required for Pomeranz-Fritsch cyclization under sufficiently mild conditions to prepare a broad range of 1,2-DHIQ products. We also demonstrate the synthetic value of these DHIQs by further functionalization to either reduced tetrahydroisoquinoline (THIQ) or fully aromatized IQ natural products.
- Ji, Xiang,Huang, Zheng,Lumb, Jean-Philip
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p. 1062 - 1072
(2020/01/31)
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- Ultrasound assisted one-pot synthesis of benzo-fused indole-4,9-dinones from 1,4-naphthoquinone and α-aminoacetals
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A one-pot synthesis of benzo[f]indole-4,9-diones from 1,4-naphthoquinone with α-aminoacetals has been developed. This method provides a straightforward synthesis of benzo[f]indole-4,9-diones via intramolecular nucleophilic attack of aminoquinones to aldehydes under mild reaction conditions. The detailed mechanism was also investigated.
- Luu, Quang H.,Guerra, Jorge D.,Casta?eda, Cecilio M.,Martinez, Manuel A.,Saunders, Jong,Garcia, Benjamin A.,Gonzales, Brenda V.,Aidunuthula, Anushritha R.,Mito, Shizue
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supporting information
p. 2253 - 2256
(2016/05/10)
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- Potent and selective xanthine-based inhibitors of phosphodiesterase 5
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Inhibitors of PDE5 are useful therapeutic agents for treatment of erectile dysfunction. A series of novel xanthine derivatives has been identified as potent inhibitors of PDE5, with good levels of selectivity against other PDE isoforms, including PDE6. St
- Arnold, Nichola J.,Arnold, Ruth,Beer, David,Bhalay, Gurdip,Collingwood, Stephen P.,Craig, Sarah,Devereux, Nicholas,Dodds, Mark,Dunstan, Andrew R.,Fairhurst, Robin A.,Farr, David,Fullerton, Joseph D.,Glen, Angela,Gomez, Sylvie,Haberthuer, Sandra,Hatto, Julia D.I.,Howes, Colin,Jones, Darryl,Keller, Thomas H.,Leuenberger, Beate,Moser, Heinz E.,Muller, Irene,Naef, Reto,Nicklin, Paul A.,Sandham, David A.,Turner, Katharine L.,Tweed, Morris F.,Watson, Simon J.,Zurini, Mauro
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p. 2376 - 2379
(2007/10/03)
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