- Asymmetric synthesis of β-dialkylamino alcohols by transfer hydrogenation of α-dialkylamino ketones
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Transfer hydrogenation of representative aryl and heteroaryl dialkylaminomethyl ketones with formic acid-triethylamine, catalyzed by RuCl[(R,R)-TsDPEN](η-p-cymene), produces the corresponding β-dialkylamino alcohols, 97-99% ee, in 50-73% yields. Asymmetric synthesis of (R)-macromerine, 98% ee, the cactus Coryphantha macromeris alkaloid, is also described.
- Kosmalski, Tomasz,Wojtczak, Andrzej,Zaidlewicz, Marek
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- Enantioselective synthesis of optically active β-aminoalcohols via asymmetric reduction
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Optically active β-aminoalcohol derivatives were prepared by asymmetric reduction of the corresponding aminoketones with a chiral borohydride, K glucoride (1).
- Cho,Chun
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- Tridentate nitrogen phosphine ligand containing arylamine NH as well as preparation method and application thereof
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The invention discloses a tridentate nitrogen phosphine ligand containing arylamine NH as well as a preparation method and application thereof, and belongs to the technical field of organic synthesis. The tridentate nitrogen phosphine ligand disclosed by the invention is the first case of tridentate nitrogen phosphine ligand containing not only a quinoline amine structure but also chiral ferrocene at present, a noble metal complex of the type of ligand shows good selectivity and extremely high catalytic activity in an asymmetric hydrogenation reaction, meanwhile, a cheap metal complex of the ligand can also show good selectivity and catalytic activity in the asymmetric hydrogenation reaction, and is very easy to modify in the aspects of electronic effect and space structure, so that the ligand has huge potential application value. A catalyst formed by the ligand and a transition metal complex can be used for catalyzing various reactions, can be used for synthesizing various drugs, and has important industrial application value.
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Paragraph 0095-0102; 0105-0109
(2021/06/26)
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- Electroreductive generation of (S)-(+)-N,N-dimethyl-2-(hydroxymethyl)- pyrrolidinium mercury compound for enantioselective synthesis of 2-amino-1-alkyl/aryl ethanols
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(S)-(+)-N, N - Dimethyl-2-(hydroxymethyl)-pyrrolidinium (DMHP +)-mercury compound mediated enantioselective reduction of aminomethyl alkyl/aryl ketones in dimethylformamide-2-propanol (9:1) has been carried out using tetrabutylammonium tetrafluoroborate as a supporting electrolyte. The products viz. 2-amino-1-alkyl/aryl ethanols have been obtained in good yield (68-92%) with 35-91% optical purity and have been assigned (S)-configuration. The pinacol (racemic/meso) derivatives are also isolated as minor products (yield 5-20%) via dimerization of radical anion followed by protonation.
- Yadav, Ashok K.,Manju, Meera
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p. 2770 - 2772
(2008/04/18)
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- Optimisation of enantioselectivity for the chiral base-mediated rearrangement of bis-protected meso-4,5-dihydroxycyclohexene oxides: Asymmetric synthesis of 4-deoxyconduritols and conduritol F
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A strategy based on diastereoselective epoxidation of a cyclohexene followed by chiral lithium amide-mediated epoxide rearrangement has been used to synthesise an allylic alcohol building block of >95% ee. The key step is the enantioselective rearrangement of a bis-protected meso-4,5-dihydroxycyclohexene oxide. A range of protecting groups and chiral base structures were surveyed in order to find the optimum protocol for high enantioselectivity. Using a tert-butyldimethylsilyloxy protecting group and a norephedrine-derived chiral base, a 93% yield of an allylic alcohol of >95% ee was achieved. To demonstrate the synthetic utility, this allylic alcohol was subsequently transformed into 4-deoxyconduritols and (+)-conduritol F.
- De Sousa, Simon E,O'Brien, Peter,Pilgram, Christopher D
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p. 4643 - 4654
(2007/10/03)
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- Boranes in Synthesis. 2. Asymmetric Synthesis of β-Amino Alcohols. A Facile Conversion of 2-Amino Acetophenones to the Corresponding β-Amino Alcohols in High Enantiomeric Purity
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The asymmetric reduction of 2-amino acetophenones with Ipc2BH or Ipc2BCl at -78 deg C, yields the corresponding β-amino alcohols in good to excellent yields.Although only modest (12-45percent ee) enantiomeric excesses were obtained with Ipc2BH, 75-99perce
- Beardsley, David A.,Fisher, Gary B.,Goralski, Christian T.,Nicholson, Lawrence W.,Singaram, Bakthan
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p. 1511 - 1514
(2007/10/02)
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