- Synthesis of Tetrahydroquinolines via Borrowing Hydrogen Methodology Using a Manganese PN3Pincer Catalyst
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A straightforward and selective synthesis of 1,2,3,4-tetrahydroquinolines starting from 2-aminobenzyl alcohols and simple secondary alcohols is reported. This one-pot cascade reaction is based on the borrowing hydrogen methodology promoted by a manganese(I) PN3 pincer complex. The reaction selectively leads to 1,2,3,4-tetrahydroquinolines thanks to a targeted choice of base. This strategy provides an atom-efficient pathway with water as the only byproduct. In addition, no further reducing agents are required.
- Hofmann, Natalie,Homberg, Leonard,Hultzsch, Kai C.
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supporting information
p. 7964 - 7970
(2020/11/02)
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- Unsupported nanoporous gold catalyst for highly selective hydrogenation of quinolines
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For the first time, the highly efficient and regioselective hydrogenation of quinoline derivatives to 1,2,3,4-tetrahydroquinolines using unsupported nanoporous gold (AuNPore) as a catalyst and organosilane with water as a hydrogen source is reported. The AuNPore catalyst can be readily recovered and reused without any loss of catalytic activity.
- Yan, Mei,Jin, Tienan,Chen, Qiang,Ho, Hon Eong,Fujita, Takeshi,Chen, Lu-Yang,Bao, Ming,Chen, Ming-Wei,Asao, Naoki,Yamamoto, Yoshinori
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supporting information
p. 1484 - 1487
(2013/06/26)
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- The remarkable effect of a simple ion: Iodide-promoted transfer hydrogenation of heteroaromatics
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I can do it! Accelerated by simple iodide ions, rhodium-catalysed transfer hydrogenation can be readily performed on quinolines, isoquinolines and quinoxalines, affording the tetrahydro products in high yields with low catalyst loading (see scheme). Copyright
- Wu, Jianjun,Wang, Chao,Tang, Weijun,Pettman, Alan,Xiao, Jianliang
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supporting information; experimental part
p. 9525 - 9529
(2012/08/28)
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- Synthesis of alkaloids of Galipea officinalis by alkylation of an α-amino nitrile
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A new synthetic approach directed towards the synthesis of naturally occurring 2-alkyl-tetrahydroquinolines is described. The C-C bonds in the α position relative to the nitrogen atom were formed by the reversal of the polarity of the C=N bond of α-amino nitrile 6, which was prepared electrochemically from 1-(phenylethyl)-tetrahydroquinoline. A NaBH 4-mediated reductive decyanation process furnished benzylic amines 16a-d as mixtures of diastereomers (50-60% de). The catalytic hydrogenolysis of these amines was performed in the presence of Pearlman's catalyst to give the tetrahydroquinolines 17a-d in yields ranging from 70% to 95%. Methylation of the free nitrogen atom afforded the title compounds 1-4 in 70-90% yields. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Shahane, Saurabh,Louafi, Fadila,Moreau, Julie,Hurvois, Jean-Pierre,Renaud, Jean-Luc,Van De Weghe, Pierre,Roisnel, Thierry
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experimental part
p. 4622 - 4631
(2009/05/07)
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- Indium metal as a reducing agent in organic synthesis
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The low first ionisation potential (5.8 eV) of indium coupled with its stability towards air and water, suggest that this metallic element should be a useful reducing agent for organic substrates. The use of indium metal for the reduction of C=N bonds in imines, the heterocyclic ring in benzo-fused nitrogen heterocycles, of oximes, nitro compounds and conjugated alkenes and the removal of 4-nitrobenzyl protecting groups is described. Thus the heterocyclic ring in quinolines, isoquinolines and quinoxalines is selectively reduced using indium metal in aqueous ethanolic ammonium chloride. Treatment of a range of aromatic nitro compounds under similar conditions results in selective reduction of the nitro groups; ester, nitrile, amide and halide substituents are unaffected. Likewise indium in aqueous ethanolic ammonium chloride is an effective method for the deprotection of 4-nitrobenzyl ethers and esters. Indium is also an effective reducing agent under non-aqueous conditions and α-oximino carbonyl compounds can be selectively reduced to the corresponding N-protected amine with indium powder, acetic acid in THF in the presence of acetic anhydride or di-tert-butyl dicarbonate. Conjugated alkenes are also reduced by indium in THF-acetic acid.
- Pitts,Harrison,Moody
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p. 955 - 977
(2007/10/03)
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- Switching Androgen Receptor Antagonists to Agonists by Modifying C-Ring Substituents on Piperidinoquinolinone
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New nonsteroidal human androgen receptor (hAR) agonists were developed from an hAR antagonist pharmacophore, 2(1H-piperidinoquinolinone. (+/-)-trans-7,8-diethyl-4-trifluoromethyl-2(1H)-piperidinoquinolinone was synthesized and demonstrated p
- Zhi, Lin,Tegley, Christopher M.,Marschke, Keith B.,Jones, Todd K.
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p. 1008 - 1012
(2007/10/03)
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- Regioselectivity in Forming Dipole-Stabilized Anions. Sites of Metalation of Indolines, Tetrahydroquinolines, and Benzazepines Activated by N-Formimidoyl or N-Boc Groups
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Metalation of the title compounds indicated that the formamidine-equipped indolines or 1,2,3,4-tetrahydroquinolines give rise solely to C-2 alkylation products (5,6) whereas the corresponding N-t-Boc systems give only ortho aryl alkylation (7,8).
- Meyers, A. I.,Milot, Guy
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p. 6538 - 6540
(2007/10/02)
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- Palladium-Assisted N-Alkylation of Indoles: Attempted Application to Polycyclization
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The palladium(II) complexes of the olefins ethene, propene, and 1-hexene reacted with 1-lithioindole to produce N-alkylated indoles exclusively.Attempts to perform this N-alkylation intramoleculary (to form tricyclic material from 2-allylskatole) failed.Anilines with dienic side chains in the 2-position were subjected to Pd(II)-assisted cyclization conditions in attempts to induce polycyclization.However, only monocyclization was observed.
- Hegedus, Louis S.,Winton, Peter M.,Varaprath Sudarsanan
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p. 2215 - 2221
(2007/10/02)
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