Journalartikel

Jahr der Veröffentlichung: 2016

Seiten: 15754-15759

Zeitschrift: Angewandte Chemie International Edition

Bandnummer: 55

Heftnummer: 51

DOI Link: https://doi.org/10.1002/anie.201608559

Verlag: Wiley

Abstract: 

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 T₁
relaxation 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.

Harvard-Zitierstil: Prochazkova, E., Kolmer, A., Ilgen, J., Schwab, M., Kaltschnee, L., Fredersdorf, M., et al. (2016) Uncovering Key Structural Features of an Enantioselective Peptide‐Catalyzed Acylation Utilizing Advanced NMR Techniques, Angewandte Chemie International Edition, 55(51), pp. 15754-15759. https://doi.org/10.1002/anie.201608559

APA-Zitierstil: Prochazkova, E., Kolmer, A., Ilgen, J., Schwab, M., Kaltschnee, L., Fredersdorf, M., Schmidts, V., Wende, R., Schreiner, P., & Thiele, C. (2016). Uncovering Key Structural Features of an Enantioselective Peptide‐Catalyzed Acylation Utilizing Advanced NMR Techniques. Angewandte Chemie International Edition. 55(51), 15754-15759. https://doi.org/10.1002/anie.201608559