Conformational preferences of fluorine-containing agrochemicals and their implications for lipophilicity prediction

• Daniela Rodrigues Silva,
• Joyce K. Daré and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2020, 16, 2469–2476, doi:10.3762/bjoc.16.200

• ]. Thus, a different μ was calculated for each of the three staggered conformers of I and a weighted average μ was obtained from the calculated μ of the three conformers Igg, Iag, and Iga. Then, the calculated μ values were plotted against the experimental log P (Figure 5a) in order to quantitatively

Homo- and hetero-difunctionalized β-cyclodextrins: Short direct synthesis in gram scale and analysis of regiochemistry

• Gábor Benkovics,
• Mihály Bálint,
• Éva Fenyvesi,
• Erzsébet Varga,
• Szabolcs Béni,
• Konstantina Yannakopoulou and
• Milo Malanga

Beilstein J. Org. Chem. 2019, 15, 710–720, doi:10.3762/bjoc.15.66

• allowed the identification of the spin system of each glucopyranose unit among which the tosylated ones can be identified using the resonance frequencies of H6,6’ as an entry point. Three staggered conformers with respect to the TsO–C(6)–C(5)–H(5) dihedral angle (see Figure 3d for numbering) are possible

Remarkable functions of sn-3 hydroxy and phosphocholine groups in 1,2-diacyl-sn-glycerolipids to induce clockwise (+)-helicity around the 1,2-diacyl moiety: Evidence from conformation analysis by ¹H NMR spectroscopy

• Yoshihiro Nishida,
• Mengfei Yuan,
• Kazuo Fukuda,
• Kaito Fujisawa,
• Hirofumi Dohi and
• Hirotaka Uzawa

Beilstein J. Org. Chem. 2017, 13, 1999–2009, doi:10.3762/bjoc.13.196

• phosphates). The 1H NMR analysis indicated that the helical property around the 1,2-diacyl moiety is considerably affected by these sn-3 substituents. The sn-3 hydroxy group induced a unique helical property, which was considerably dependent on the solvents used. In CDCl3 solution, three staggered conformers

• ; deuterium labeling; sn-glycerol; glycerolipids; glycerophospholipids; helicity; Karplus equation; proton NMR spectroscopy; staggered conformers; Introduction Glycerophospholipids, constituting the basic elements of cytoplasm bilayer membranes, are responsible for several cell functions [1][2][3]. These

• populations (%) of the three staggered conformers [gt(+), gg(−) and tg] are calculated using two Karplus equations, Equation 1 [22] and Equation 2 [18]. From the conformer populations (%), the “helicity index” is determined according to the method previously reported by our group [18]. The result in entry 1

An easy α-glycosylation methodology for the synthesis and stereochemistry of mycoplasma α-glycolipid antigens

• Yoshihiro Nishida,
• Yuko Shingu,
• Yuan Mengfei,
• Kazuo Fukuda,
• Hirofumi Dohi,
• Sachie Matsuda and
• Kazuhiro Matsuda

Beilstein J. Org. Chem. 2012, 8, 629–639, doi:10.3762/bjoc.8.70

• , each of them is allowed to have three staggered conformers of gg (gauche-gauche), gt (gauche-trans) and tg (trans-gauche) (Figure 3). In solution and also in self-contacting liquid-crystalline states, these conformers are thought to equilibrate with each other. In this study, we calculated time

The C–F bond as a conformational tool in organic and biological chemistry

• Luke Hunter

Beilstein J. Org. Chem. 2010, 6, No. 38, doi:10.3762/bjoc.6.38

• in these systems. Hyperconjugation effects Consider the well-studied molecule 1,2-difluoroethane (11, Figure 1c). There are two possible staggered conformers, with the fluorine atoms either gauche or anti. NMR and molecular modelling studies have shown that the gauche conformer is lower in energy

The vicinal difluoro motif: The synthesis and conformation of erythro- and threo- diastereoisomers of 1,2-difluorodiphenylethanes, 2,3-difluorosuccinic acids and their derivatives

• David O'Hagan,
• Henry S. Rzepa,
• Martin Schüler and
• Alexandra M. Z. Slawin

Beilstein J. Org. Chem. 2006, 2, No. 19, doi:10.1186/1860-5397-2-19

• ). Conformational energy calculations on erythro and threo-13 Due to the ambiguous solution state study particularly for erythro-13, ab initio calculations were carried out at the B3LYP//cc-pVTZ level exploring absolute energies of the three staggered conformers of both erythro- and threo- 13 [24][25]. The

• Information File 2). Of the three staggered conformers of the erythro-13 isomer two are enantiomeric and have identical energies thus analysis of erythro-13 is reduced to a comparison of the energies of conformers a and b. Conformer a emerges as the more stable in the gas phase, with this stability

• ' spin systems in the 1H-NMR (left) and 19F-NMR spectra (right) of erythro-13 (a), threo-13 (b) and the four individual coupling constants for the central 1H and 19F nuclei are given in (c). NMR coupling constants and calculated relative energies (kcalmol-1) of the staggered conformers of erythro- and