- Simple primary β-amino alcohols as organocatalysts for the asymmetric Michael addition of β-keto esters to nitroalkenes
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Simple primary β-amino alcohols act as an efficient organocatalysts in the asymmetric Michael addition of β-keto esters with nitroalkenes affording highly pure chiral Michael adducts. Also, both enantiomers of the adducts were obtained, depending on the specific catalyst used and reaction temperature.
- Begum, Zubeda,Sannabe, Haruka,Seki, Chigusa,Okuyama, Yuko,Kwon, Eunsang,Uwai, Koji,Tokiwa, Michio,Tokiwa, Suguru,Takeshita, Mitsuhiro,Nakano, Hiroto
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p. 203 - 209
(2021/02/09)
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- Simple primary β-amino alcohol catalyzed enantioselective Diels-Alder reaction of 3-hydroxy-2-pyridones
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The simple primary β-amino alcohol catalyzed Diels-Alder reaction of 3-hydroxy-2-pyridones as dienes with N-substituted maleimides to provide the highly substituted optically active isoquinuclidines as a single diastereomers in excellent enantioselectivities (up to 98%) with excellent chemical yields (up to 95%) was demonstrated. A range of simple β-amino alcohols were synthesized from the corresponding inexpensive amino acids and their catalytic activity was examined for this reaction.
- Takahashi, Toshihisa,Subba Reddy,Kohari, Yoshihito,Seki, Chigusa,Furuyama, Taniyuki,Kobayashi, Nagao,Okuyama, Yuko,Kwon, Eunsang,Uwai, Koji,Tokiwa, Michio,Takeshita, Mitsuhiro,Nakano, Hiroto
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p. 5771 - 5776
(2016/12/03)
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- Silyloxy Amino Alcohol Organocatalyst for Enantioselective 1,3-Dipolar Cycloaddition of Nitrones to α,β-Unsaturated Aldehydes
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The catalytic activity of a simple amino alcohol that contains a bulky super silyl group [i.e., tris(trimethylsilyl)silyl (TTMSS)] bonded to the oxygen atom at the γ-position along with a primary amine moiety was examined in the enantioselective 1,3-dipolar cycloaddition of nitrones to α,β-unsaturated aldehydes. The organocatalyst successfully provided optically active isoxazolidines in good chemical yields (up to 86 %) with excellent diastereoselectivities (endo/exo, up to 96:4) and enantioselectivities (up to 97 % ee). Furthermore, the obtained isoxazolidines were easily converted into γ-amino diols that contain three contiguous stereogenic centers.
- Otsuki, Teppei,Kumagai, Jun,Kohari, Yoshihito,Okuyama, Yuko,Kwon, Eunsang,Seki, Chigusa,Uwai, Koji,Mawatari, Yasuteru,Kobayashi, Nagao,Iwasa, Tatsuo,Tokiwa, Michio,Takeshita, Mitsuhiro,Maeda, Atushi,Hashimoto, Akihiko,Turuga, Kana,Nakano, Hiroto
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p. 7292 - 7300
(2015/11/25)
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- Chiral Bis(oxazolidine)pyridine-copper-catalyzed enantioselective friedel-crafts alkylation of indoles with nitroalkenes
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Catalytic asymmetric Friedel-Crafts reaction of indoles with nitroalkenes was catalyzed by the stereochemically tunable bis(oxazolidine)pyridine (PyBodine)-Cu(OTf)2 complex. Using the PyBodine(Val)-Cu(OTf) 2 catalyst gave the Friedel-Crafts ?adducts with highly enantioselective manner. For the 1,4-bis[(E)-2-nitrovinyl]benzene, the reaction proceeded in a meso-trick manner to give the chiral double Friedel-Crafts adduct with 97% enantiomeric excess. Georg Thieme Verlag Stuttgart New York.
- Sato, Toru,Arai, Takayoshi
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p. 349 - 354
(2014/03/21)
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- Tridentate ligands derived from L-tert-Leucine for the Cu(II) mediated asymmetric Henry reaction
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Chiral tridentate Schiff base ligands were prepared from L-tert-Leucine and used as catalysts in the asymmetric Henry reaction in the presence of Cu(II) ions. Moderate enantiomeric excesses (up to 66%) and yields (up to 76%) of the desired β-nitroalcohols were obtained. TUeBITAK.
- Korkmaz, Neslihan,Astley, Demet,Astley, Stephen T.
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p. 361 - 374
(2012/02/01)
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