- Synthesis and characterization of n-substituted (S)-1,2,3,4-tetrahydroisoquinoline-3-carboxamides and thioamides as organocatalysts for asymmetric aldol reaction
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In this paper, the preparation and characterization of eight optically pure N-functionalized (S)-1,2,3,4-tetrahydroisoquinoline-3-carboxamides and thioamides is described. The prepared amides and thioamides were tested as organocatalysts of aldol reaction of 4-nitrobenzaldehyde and acetone. The highest ee of formation of 4-hydroxy-4-(4-nitrophenyl)butan-2-one was obtained with (S)-N-[(1R)-1-phenylethyl]-1,2,3,4-tetrahydroisoquinoline-3-thiocarboxamide (77% ee). The observed deceleration of the aldol reaction catalyzed in this way, as compared with that catalyzed with (S)-proline, was attributed to the formation of little reactive cyclic intermediate, which was isolated and characterized.
- Androvic, Ladislav,Drabina, Pavel,Panov, Illia,Harmand, Lydie,Padelkova, Zdenka,Sedlak, Milos
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p. 1844 - 1859
(2014/08/18)
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- Asymmetric conjugate addition of thioglycolate to a range of chalcones using tetrahydroisoquinoline (TIQ) N,N′-dioxide ligands
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A series of novel TIQ based N,N′-oxide ligands were synthesised and screened for their catalytic activity in the enantioselective conjugate addition of thioglycolate to chalcones. Bulky groups on the side chain of the TIQ backbone provided the highest enantioselectivity of up to 88% with 10 mol % catalyst loading. It was also observed that these reactions proceeded optimally in the presence of dichloromethane as a solvent. Screening of various metals emphasized La(OTf)3 as the ideal pre-catalyst for this particular reaction.
- Chakka, Sai Kumar,Cele, Zamani E.D.,Sosibo, Sphelele C.,Francis, Vivian,Arvidsson, Per I.,Kruger, Hendrik G.,Maguire, Glenn E.M.,Govender, Thavendran
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experimental part
p. 616 - 622
(2012/08/27)
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- Synthesis of tetrahydroisoquinoline-diamine ligands and their application in asymmetric transfer hydrogenation
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The use of the tetrahydroisoquinoline scaffold is well documented in biologically active compounds. However, reports of the utilisation of tetrahydroisoquinoline compounds in asymmetric catalysis are limited. The synthesis of novel diamine ligands possessing the tetrahydroisoquinoline (tetrahydroisoquinoline) backbone and evaluation of their activity in the asymmetric transfer hydrogenation of acetophenone are presented. The diamine ligands in conjunction with i-PrOH as the hydrogen source and [RhCl2(Cp*)]2 as the metal precursor proved to be the most effective of the tetrahydroisoquinoline derivatives for this catalytic system. Water was found to have a profound influence on the enantioselectivity of the reaction. Optimisation of the amount water, i-PrOH and catalytic loading content rendered the best result of 70% enantioselectivity for the (S)-1-phenylethanol isomer product.
- Peters, Byron K.,Chakka, Sai Kumar,Naicker, Tricia,Maguire, Glenn E.M.,Kruger, Hendrik G.,Andersson, Pher G.,Govender, Thavendran
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experimental part
p. 679 - 687
(2010/07/17)
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- New P-stereogenic triaminophosphines and their derivatives: Synthesis, structure, conformational study, and application as chiral ligands
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The synthesis, structural, and conformational studies of new P-chiral triaminophosphines, which feature an indolidine and a 1,2,3,4- tetrahydroquinolidine pattern, respectively, are reported. These compounds can feature very different 3D-structures, although they both could be seen a priori as close derivatives of the previously reported 3-phenyl-1,3-diaza-2- phosphabicyclo[3.3.0]octane. The consequences for the use of such compounds and their derivatives in asymmetric metal-catalysis are discussed on the basis of preliminary results in asymmetric cobalt-catalyzed [6+2] cycloaddition.
- Toselli, Nicolas,Fortrie, Remy,Martin, David,Buono, Gerard
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experimental part
p. 1238 - 1245
(2010/11/02)
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- Optimized synthesis of tetrahydroisoquinoline-hydantoins
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Several methods have been developed and compared for the solution synthesis of tetrahydroisoquinoline-hydantoin derivatives. The best yields were obtained when the imidazolidine-2,4-dione ring was synthesized in two steps: (1) reaction of Tic-OH with the appropriate amine and (2) cyclization with 1,1′-carbonyldiimidazole.
- Charton, Julie,Gassiot, Amaury Cazenave,Melnyk, Patricia,Girault-Mizzi, Sophie,Sergheraert, Christian
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p. 7081 - 7085
(2007/10/03)
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