A versatile route towards 6-arylpipecolic acids

• Erich Gebel,
• Cornelia Göcke,
• Carolin Gruner and
• Norbert Sewald

Beilstein J. Org. Chem. 2025, 21, 1104–1115, doi:10.3762/bjoc.21.88

• accordance with coupling constants and resulting dihedral angles. Keywords: conformational restraints; dihedral angle NMR; half-chair conformation; modified amino acids; pipecolic acid; stereoselective hydrogenation; Suzuki–Miyaura cross-coupling; Introduction Non-proteinogenic amino acids play an

• favourable chair conformation with the aryl substituent and the methyl ester in equatorial positions (Figure 3), providing further evidence for conformational restraints (pseudoallyl strain) enforced by the formyl group. This behaviour is observable in all NMR spectra of the compound array of the reduction

How and why plants and human N-glycans are different: Insight from molecular dynamics into the “glycoblocks” architecture of complex carbohydrates

• Carl A. Fogarty,
• Aoife M. Harbison,
• Amy R. Dugdale and
• Elisa Fadda

Beilstein J. Org. Chem. 2020, 16, 2046–2056, doi:10.3762/bjoc.16.171

• -3)-Fuc or β(1-2)-Xyl. Indeed, we see here again the 20° rotation of the chitobiose GlcNAc-β(1-4)-GlcNAc psi angle caused by the stacking of the α(1-3)-Fuc to the chitobiose β(1-4)-GlcNAc and the conformational restraints imposed by the β(1-2)-Xyl on the (1-3) arm, see Table S5 in Supporting

Binding abilities of polyaminocyclodextrins: polarimetric investigations and biological assays

• Marco Russo,
• Daniele La Corte,
• Annalisa Pisciotta,
• Serena Riela,
• Rosa Alduina and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2017, 13, 2751–2763, doi:10.3762/bjoc.13.271

• indicate that binding inside the host cavity is mainly affected by interplay between Coulomb interactions and conformational restraints. Moreover, simultaneous interaction of the cationic polyamine pendant bush at the primary rim was positively assessed. Insights on quantitative aspects of the interaction

• interactions, medium effects and conformational restraints, with a subtle interplay determining the occurrence of non-linear data trends in some cases. Therefore, the behavior observed and the relevant rationalization proposed by us, appear perfectly consistent with the previous literature on the topic [50

Binding abilities of a chiral calix[4]resorcinarene: a polarimetric investigation on a complex case of study

• Marco Russo and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2017, 13, 2698–2709, doi:10.3762/bjoc.13.268

• significant downfield shift and splitting is shown by the proline-H(2) signal (from 2.79 to 2.91–3.03 ppm), whereas a fair upfield shift is found for one of the N-methylene H atoms (from 3.81 to 3.77 ppm), which account for the possible conformational restraints on the proline-decorated rim occurring upon

Effects of anion complexation on the photoreactivity of bisureido- and bisthioureido-substituted dibenzobarrelene derivatives

• Heiko Ihmels and
• Jia Luo

Beilstein J. Org. Chem. 2011, 7, 278–289, doi:10.3762/bjoc.7.37

• substituent. Presumably, in complex 1h-SMD one initial vinyl–benzo bridging (pathway a or b) is preferred due to steric or conformational restraints; however, this effect is only small, but significant, as indicated by the moderate stereoselectivity (68:32 er). At present, the reason for the lack of