64715-85-1Relevant articles and documents
Monofluoroalkene-Isostere as a 19F NMR Label for the Peptide Backbone: Synthesis and Evaluation in Membrane-Bound PGLa and (KIGAKI)3
Drouin, Myriam,Wadhwani, Parvesh,Grage, Stephan L.,Bürck, Jochen,Reichert, Johannes,Tremblay, Sébastien,Mayer, Marie Sabine,Diel, Christian,Staub, Alexander,Paquin, Jean-Fran?ois,Ulrich, Anne S.
, p. 1511 - 1517 (2020/02/05)
Solid-state 19F NMR is a powerful method to study the interactions of biologically active peptides with membranes. So far, in labelled peptides, the 19F-reporter group has always been installed on the side chain of an amino acid. Given the fact that monofluoroalkenes are non-hydrolyzable peptide bond mimics, we have synthesized a monofluoroalkene-based dipeptide isostere, Val-Ψ[(Z)-CF=CH]-Gly, and inserted it in the sequence of two well-studied antimicrobial peptides: PGLa and (KIGAKI)3 are representatives of an α-helix and a β-sheet. The conformations and biological activities of these labeled peptides were studied to assess the suitability of monofluoroalkenes for 19F NMR structure analysis.
Origins of stereoselectivity in optically pure phenylethaniminopyridine tris-chelates M(NN′)3n+ (M = Mn, Fe, Co, Ni and Zn)
Howson, Suzanne E.,Allan, Laura E. N.,Chmel, Nikola P.,Clarkson, Guy J.,Deeth, Robert J.,Faulkner, Alan D.,Simpson, Daniel H.,Scott, Peter
, p. 10416 - 10433 (2011/11/13)
One-pot reactions of 2-pyridinecarboxaldehyde, chiral phenylethanamines and Fe(ii) give single diastereomer fac diimine complexes at thermodynamic equilibrium so that no chiral separations are required (d.r. > 200:1). The origins of this stereoselectivity are partly steric and partly a result of the presence of three sets of inter-ligand parallel-offset π-stacking interactions. Mn(ii), Co(ii), Co(iii), Ni(ii) and Zn(ii) give similar fac structures, alongside the imidazole analogues for Fe(ii). While most of the complexes are paramagnetic, the series of molecular structures allows us to assess the influence of the π-stacking present, and there is a strong correlation between this and the M-N bond length. Fe(ii) is close to optimal. For the larger Zn(ii) ion, very weak π-stacking leads to poorer measured stereoselectivity (NMR) but this is improved with increased solvent polarity. The mechanism of stereoselection is further investigated via DFT calculations, chiroptical spectroscopy and the use of synthetic probes.
Chemoselective and stereoselective synthesis of gem-difluoro-β-aminoesters or gem-difluoro-β-lactams from ethylbromodifluoroacetate and imines during Reformatsky reaction
Boyer, Nicolas,Gloanec, Philippe,De Nanteuil, Guillaume,Jubault, Philippe,Quirion, Jean-Charles
, p. 12352 - 12366 (2008/03/12)
The chemoselective and stereoselective synthesis of gem-difluoro-β-aminoesters or gem-difluoro-β-lactams was investigated from ethylbromodifluoroacetate and imines during Reformatsky reaction. Influence of various reaction parameters, such as nature of the amine part, nature of the chiral auxiliary, was evaluated. High levels of stereoselectivity (up to 98%) were obtained for gem-difluoro-β-aminoesters and gem-difluoro-β-lactams using either (R)-phenylglycinol or (R)-methoxyphenylglycinol.