- Bianthryl-based organocatalysts for the asymmetric Henry reaction of fluoroketones
-
We have developed a catalytic system based on bianthrylbis(thiourea) for the asymmetric Henry reaction of fluoroketones and nitroalkanes that resulted from the screening of a library containing 31 chiral non-racemic organocatalysts. The corresponding adducts were isolated in up to 6 times shorter reaction time in comparison with the previously published organocatalysts. High levels of stereocontrol have been generally observed, with measured product enantiomeric excesses up to 97% and diastereomeric ratio 3:2 (anti/syn). The above-mentioned catalysts have been successfully applied to the total asymmetric synthesis of CF3-tethered (S)-halostachines, which has proved that this method constitutes an easy entry to similar enantiopure compounds.
- Otevrel, Jan,Svestka, David,Bobal, Pavel
-
supporting information
p. 5244 - 5248
(2019/06/07)
-
- Optically pure 1 - (α-aminobenzyl) - 2-naphthol preparation method
-
The invention provides a preparation method of optical pure 1-(alpha-amino benzyl)-2-naphthol. The preparation method comprises the following steps: catalytically synthesizing racemic 1-(alpha-amino benzyl)-2-naphthol trifluoroacetate by utilizing trifluoroacetic acid; and splitting racemic 1-(alpha-amino benzyl)-2-naphthol and trifluoroacetate thereof by utilizing optical pure 1, 1'-binaphthol phosphate ester and optical pure 1, 1'-binaphthol sodium phosphate as splitting reagents to prepare optical pure 1-(alpha-amino benzyl)-2-naphthol. The method is good in repeatability, and the splitting reagents can be repeatedly used, so that the method is low in cost, environment-friendly and energy-saving, and suitable for large-scale preparation of optical pure 1-(alpha-amino benzyl)-2-naphthol.
- -
-
-
- Development of chiral heteroleptic magnesium amides; Asymmetric deprotonations mediated by six-membered metallocyclic amidomagnesium naphtholates
-
A series of enantioenriched six-membered metallocyclic amidomagnesium naphtholates were prepared and used to probe the structure-reactivity/selectivity relationships of heteroleptic magnesium base complexes within asymmetric deprotonation reactions. An ef
- Carswell, Emma L.,Kerr, William J.,McArthur, Duncan,Pa?icky, Marek,Watson, Allan J.B.
-
p. 7344 - 7349
(2016/01/25)
-
- A new method for the synthesis of enantiomerically pure Betti base
-
We have developed a new method for the synthesis of enantiomerically pure Betti base. By using trifluoroacetic acid to replace the more traditionally used hydrochloride acid, the hydrolysis procedure used in the classical synthesis of racemic Betti base was carried out under milder conditions with an improved yield (up to 96%), which was followed by a new and efficient resolution with using recyclable (R)-1,1′-binaphthalene-2,2′-diyl sodium phosphate to provide enantiomerically pure (S)-Betti base in 95% yield with up to 99% ee and (R)-Betti base in 93% yield with 90% ee in one resolution step. Georg Thieme Verlag Stuttgart - New York.
- Bian, Guangling,Yang, Shiwei,Huang, Huayin,Song, Ling
-
p. 899 - 902
(2013/05/22)
-
- Synthesis, antimicrobial and cytotoxicity study of 1,3-disubstituted-1H- naphtho[1,2-e][1,3]oxazines
-
A series of new 1,3-disubstituted-1H-naphtho[1,2-e][1,3]oxazines (3 and 7) was synthesized in good yields and the structure was determined with the help of NMR, 2D-NMR, HRMS studies and X-ray crystallography. These compounds were tested in vitro for their
- Verma, Vikas,Singh, Kuldeep,Kumar, Devinder,Klap?tke, Thomas M.,Stierstorfer, J?rg,Narasimhan, Balasubramanian,Qazi, Asif Khurshid,Hamid, Abid,Jaglan, Sundeep
-
p. 195 - 202
(2013/01/15)
-
- High-performance liquid chromatographic enantioseparation of Betti base analogs on a newly developed isopropyl carbamate-cyclofructan6-based chiral stationary phase
-
The direct separation of the enantiomers of 1-(α-aminoarylmethyl)-2- naphthol, 1-(α-aminoalkyl)-2-naphthol, 2-(α-aminoarylmethyl)-1- naphthol analogs, and 2-(1-amino-2-methylpropyl)-1-naphthol) was performed on a newly developed chiral stationary phase containing isopropyl carbamate-cyclofructan6 as chiral selector, with n-heptane/alcohol/ trifluoroacetic acid as mobile phase. The effects of the mobile-phase composition, the nature and concentration of the alcoholic and acidic modifiers, and the structures of the analytes on the retention and resolution were investigated. In some cases, separations were carried out at constant mobile-phase compositions in the temperature range 5-40°C. Thermodynamic parameters and Tiso values were calculated from plots of ln k′ or ln α versus 1/T. -Δ(ΔH°) ranged from 2.8 to 3.2 kJ mol-1, -Δ(ΔS°) from 7.7 to 10.1 J mol-1 K-1, and -Δ(ΔG°) from 0.2 to 0.5 kJ mol-1. It was found that the enantioseparations were enthalpy driven. The sequence of elution of the stereoisomers determined in some cases was (R) (S).
- Aranyi, Anita,Ilisz, Istvan,Pataj, Zoltan,Szatmari, Istvan,Fueloep, Ferenc,Armstrong, Daniel W.,Peter, Antal
-
experimental part
p. 549 - 556
(2012/01/05)
-
- One-pot, three-component uncatalyzed quantitative synthesis of new aminonaphthols (Betti bases) in water
-
One-pot, three-component reaction of 2-naphthol, aromatic aldehyde, and heteroaryl amine in water at room temperature leads to the formation of the corresponding aminonaphthols (Betti bases). Reaction details and study of enantiomeric resolution of 1-(p-m
- Ghandi, Mehdi,Olyaei, Abolfazl,Raoufmoghaddam, Saeed
-
body text
p. 4125 - 4138
(2009/04/11)
-
- Substituent effects in the ring-chain tautomerism of 1,3-diaryl-2,3-dihydro-1H-naphth[1,2-e][1,3]oxazines
-
Condensation of Betti base analogue amino naphthols with substituted benzaldehydes led to 1,3-diaryl-2,3-dihydro-1H-naphth[1,2-e][1,3]oxazines (3-9) which proved to be three-component (r1-o-r2) tautomeric mixtures in CDCl3
- Szatmári, István,Martinek, Tamás A.,Lázár, László,Fül?p, Ferenc
-
p. 2877 - 2884
(2007/10/03)
-