67081-98-5Relevant articles and documents
NOVEL COMPOUNDS
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Page/Page column 58, (2022/03/07)
The invention relates to compounds of formula (I) and to their use in treating or preventing an inflammatory disease or a disease associated with an undesirable immune response: wherein R, R1, R2 and RB are as defined herein.
2,2′-Bipyridine-α,α′-trifluoromethyl-diol ligand: Synthesis and application in the asymmetric Et2Zn alkylation of aldehydes
Lauzon, Samuel,Ollevier, Thierry
supporting information, p. 11025 - 11028 (2021/11/03)
A chiral 2,2′-bipyridine ligand (1) bearing α,α′-trifluoromethyl-alcohols at 6,6′-positions was designed in five steps affording either the R,R or S,S enantiomer with excellent stereoselectivities, i.e. 97% de, >99% ee and >99.5% de, >99.5% ee, respectively. The key step for reaching high levels of stereoselectivity was demonstrated to be the resolution of the α-CF3-alcohol using (S)-ibuprofen as the resolving agent. An initial application for the 2,2′-bipyridine-α,α′-CF3-diol ligand was highlighted in the ZnII-catalyzed asymmetric ethylation reaction of aromatic, heteroaromatic, and aliphatic aldehydes. Synergistic electron deficiency and steric hindrance properties of the newly developed ligand afforded the corresponding alcohols in good to excellent yields (up to 99%) and enantioselectivities (up to 95% ee). As observed from single crystal diffraction analysis, the complexation of the 2,2′-bipyridine-α,α′-CF3-diol ligand generates an unusual hexacoordinated ZnII.
Enantioselective Addition of Diethylzinc to Aromatic Aldehydes Using Novel Thiophene-Based Chiral Ligands
Aydin, A. E.
, p. 901 - 909 (2020/07/03)
Abstract: Chiral norephedrine-derived β-amino alcohols with a thiophene moiety were synthesized from thiophene carbaldehydes (methyl- or ethyl-substituted) and chiral amino alcohols, such as both enantiomers of norephedrine and 2-aminopropanol. The synthesized ligands were applied to the catalytic asymmetric addition of diethylzinc to aldehydes to obtain optically active alcohols with a high conversion (92%) and excellent enantioselectivities (ee up to 99%). The highest enantioselectivity (ee 99%) was obtained with p-trifluorobenzaldehyde as the substrate containing the strongly electron-acceptor CF3 group.
