189125-29-9Relevant articles and documents
Modification of the Enantioselectivity of Biocatalytic meso-Desymmetrization for Synthesis of Both Enantiomers of cis-1,2-Disubstituted Cyclohexane by Amidase Engineering
Hu, Hui-Juan,Wang, Qi-Qiang,Wang, De-Xian,Ao, Yu-Fei
, p. 4538 - 4543 (2021/08/09)
Both enantiomers of cis-1,2-disubstituted cyclohexane have been obtained enantioselectively through engineered amidase-catalyzed desymmetrization of meso carbocyclic 1,2-dicarboxamides under mild condition. Based on the enzyme-substrate binding model sugg
High-Performance Liquid Chromatographic Enantioseparation of Cyclic β-Amino Acids on Zwitterionic Chiral Stationary Phases Based on Cinchona Alkaloids
Ilisz, István,Gecse, Zsanett,Lajk?, Gyula,Forr?, Enik?,Fül?p, Ferenc,Lindner, Wolfgang,Péter, Antal
, p. 563 - 570 (2015/08/25)
Stereoselective high-performance liquid chromatographic separations of eight sterically constrained cyclic β-amino acid enantiomer pairs were carried out using the newly developed Cinchona alkaloid-based zwitterionic chiral stationary phases Chiralpak ZWIX(+) and ZWIX(-). The effects of the mobile phase composition, the nature and concentrations of the acid and base additives, the counterions and temperature on the separations were investigated. The changes in standard enthalpy, Δ(ΔH°), entropy, Δ(ΔS°), and free energy, Δ(ΔG°), were calculated from the linear van't Hoff plots derived from the ln α vs. 1/T curves in the studied temperature range (10-50°C). The values of the thermodynamic parameters depended on the nature of the selectors and the structures of the analytes. Unusual temperature behavior was observed on the ZWIX(-) column: decreased retention times were accompanied by increased separation factors with increasing temperature. On the ZWIX(+) column only enthalpically, whereas on the ZWIX(-) column both enthalpically and entropically driven separations were observed. The elution sequence was determined in all cases and was observed to be the opposite on ZWIX(+) and on ZWIX(-). Chirality 27:563-570, 2015.
Cis-2-Aminocyclohex-4-enecarboxylic acid as a new building block of helical foldamers
Kwon, Sunmi,Kang, Philjae,Choi, Moon-Gun,Choi, Soo Hyuk
, p. 3221 - 3224 (2015/05/20)
cis-2-Aminocyclohex-4-enecarboxylic acid (cis-ACHE) is a conformationally constrained β-amino acid. We showed that the conformational preference of a cis-ACHE residue is similar to that of cis-2-aminocyclohexanecarboxylic acid. α/β-Peptides that consist o
Selective synthesis of new fluorinated alicyclic β-amino ester stereoisomers
Kiss, Lorand,Forro, Eniko,Fustero, Santos,Fueloep, Ferenc
scheme or table, p. 4993 - 5001 (2011/10/09)
New fluorinated alicyclic β-amino ester stereoisomers with a cyclohexene or cyclohexane skeleton were prepared from cis- or trans-2-aminocyclohex-3-enecarboxylic acids in five or six steps through a regio- and stereoselective hydroxylation and hydroxy-fluorine exchange. Fluorinated aminoester enantiomers were synthesized from enantiopure cis- or trans-2-aminocyclohexenecarboxylic acid (prepared byenzymatic resolution of the racemic substances). New fluorinated alicyclic β-amino ester stereoisomers with a cyclohexene or cyclohexane skeleton were prepared from cis-or trans-2-aminocyclohex-3-enecarboxylicacids in five or six steps. Copyright
Enantiomeric discrimination of cyclic β-amino acids using (18-crown-6)-2,3,11,12-tetracarboxylic acid as a chiral NMR solvating agent
Chisholm, Cora D.,Fueloep, Ferenc,Forro, Eniko,Wenzel, Thomas J.
experimental part, p. 2289 - 2294 (2010/11/05)
(18-Crown-6)-2,3,11,12-tetracarboxylic acid is an excellent chiral NMR solvating agent for cyclic β-amino acids with cyclopentane, cyclohexane, cycloheptane, cyclopentene, cyclohexene, bicyclo[2.2.1]heptane, and bicyclo[2.2.1]heptene rings. The crown ether was added to the neutral β-amino acids in methanol-d4. A neutralization reaction between the crown ether and β-amino acid forms the ammonium ion needed for favorable association. Enantiomeric discrimination of the two hydrogen atoms α to the amine and carboxylic acid moieties of the β-amino acid was observed with every substrate studied. Trends in the order of the enantiomeric discrimination of certain hydrogen atoms for substrates of similar structures correlate with the absolute configuration.
Synthesis of orthogonally protected azepane β-amino ester enantiomers
Kazi, Brigitta,Kiss, Loránd,Forró, Eniko,Fül?p, Ferenc
scheme or table, p. 82 - 85 (2010/03/01)
A simple and convenient route is presented for the preparation of regio- and stereoisomers of novel azepane β-amino esters, starting from bicyclic β-lactam isomers. The synthetic procedure consists of dihydroxylation of the olefinic bond of the alicyclic amino esters, followed by NaIO4-mediated cleavage of the diol intermediate and reductive ring closure, which furnishes novel regioisomeric 5-aminoazepane-4-carboxylate and 3-aminoazepane-4-carboxylates. This method also allows the preparation of amino esters with an azepane skeleton in enantiomerically pure form.
Advanced procedure for the enzymatic ring opening of unsaturated alicyclic β-lactams
Forro, Eniko,Fueloep, Ferenc
, p. 2875 - 2880 (2007/10/03)
Enantiopure β-amino acids 1a-4a and β-lactams 1b-4b were prepared simultaneously through the lipolase-catalysed enantioselective ring opening of unsaturated racemic β-lactams (±)-1-(±)-4. High enantioselectivities (E>200) were observed when the reactions
Molecular Basis for the Enantioselective Ring Opening of β-Lactams Catalyzed by Candida antarctica Lipase B
Park, Seongsoon,Forro, Enikoe,Grewal, Harjap,Fueloep, Ferenc,Kazlauskas, Romas J.
, p. 986 - 995 (2007/10/03)
Lipase B from Candida antarctica (CAL-B) catalyzes the slow, but highly enantioselective (E>200), ring-opening alcoholysis of two bicyclic and two 4-aryl-substituted β-lactams. Surprisingly, the rate of the reaction varies with the nature of the alcohols and was fastest with either enantiomer of 2-octanol. A 0.5-g scale reaction with 2-octanol as the nucleophile in diisopropyl ether at 60°C yielded the unreacted β-lactam in 39-46% yield (maximum yield is 50%) with ≥96% ee. The product β-amino acid esters reacted further by polymerization (not isolated or characterized) or by hydrolysis due to small amounts of water in the reaction mixture yielding β-amino acids (7-11% yield, ≥96% ee). The favored enantiomer of all four β-lactams had similar 3-D orientation of substituents, as did most previously reported β-lactams and β-lactones in similar ring-opening reactions. Computer modeling of the ring opening of 4-phenylazetidin-2-one suggests that the reaction proceeds via an unusual substrate-assisted transition state, where the substrate alcohol bridges between the catalytic histidine and the nitrogen of the β-lactam. Computer modeling also suggested that the molecular basis for the high enantioselectivity is a severe steric clash between Ile189 in CAL-B and the phenyl substituent on the slow-reacting enantiomer of the β-lactam.
Enzymatic resolution of alicyclic β-lactams
Kaman, Judit,Forro, Eniko,Fueloep, Ferenc
, p. 1593 - 1600 (2007/10/03)
Racemates of N-hydroxymethylated β-lactams 4-6 were resolved through the lipase-catalyzed asymmetric acylation of the primary hydroxy group at the 6S stereogenic centre. High enantioselectivity (E>200) was observed when the enzymatic reactions were perfor
