62921-46-4Relevant articles and documents
Kinetic resolution of trans-2-acetoxycycloalkan-1-ols by lipase-catalysed enantiomerically selective acylation
Bodai, Viktoria,Orovecz, Oliver,Szakacs, Gyoergy,Novak, Lajos,Poppe, Laszlo
, p. 2605 - 2612 (2003)
Kinetic resolution of a series of racemic trans-cycloalkane-1,2-diol monoacetates rac-2a-d was performed by enantiomerically selective transesterification with vinyl acetate catalysed by commercial and our own-prepared fungal lipases to yield diacetates (
Regioselective lithiation of benzyl imidazole: Synthesis and evaluation of new organocatalysts for trans-diol functionalization.
El-Mansy, Mohamed,Ghosh, Ankan,Cheong, Paul Ha-Yeon,Carter, Rich
supporting information, p. 3131 - 3139 (2019/09/03)
Benzyl imidazole was successfully lithiated using n-BuLi at ?78 °C and verified by deuterium incorporation. The chemical reaction of the lithiated benzimidazole was explored with a series of different electrophiles. This approach was utilized to synthesiz
Uncovering Key Structural Features of an Enantioselective Peptide-Catalyzed Acylation Utilizing Advanced NMR Techniques
Procházková, Eli?ka,Kolmer, Andreas,Ilgen, Julian,Schwab, Mira,Kaltschnee, Lukas,Fredersdorf, Maic,Schmidts, Volker,Wende, Raffael C.,Schreiner, Peter R.,Thiele, Christina M.
, p. 15754 - 15759 (2016/12/16)
We report on a detailed NMR spectroscopic study of the catalyst-substrate interaction of a highly enantioselective oligopeptide catalyst that is used for the kinetic resolution of trans-cycloalkane-1,2-diols via monoacylation. The extraordinary selectivity has been rationalized by molecular dynamics as well as density functional theory (DFT) computations. Herein we describe the conformational analysis of the organocatalyst studied by a combination of nuclear Overhauser effect (NOE) and residual dipolar coupling (RDC)-based methods that resulted in an ensemble of four final conformers. To corroborate the proposed mechanism, we also investigated the catalyst in mixtures with both trans-cyclohexane-1,2-diol enantiomers separately, using advanced NMR methods such as T1relaxation time and diffusion-ordered spectroscopy (DOSY) measurements to probe molecular aggregation. We determined intramolecular distance changes within the catalyst after diol addition from quantitative NOE data. Finally, we developed a pure shift EASY ROESY experiment using PSYCHE homodecoupling to directly observe intermolecular NOE contacts between the trans-1,2-diol and the cyclohexyl moiety of the catalyst hidden by spectral overlap in conventional spectra. All experimental NMR data support the results proposed by earlier computations including the proposed key role of dispersion interaction.