Monofluoroalkene-Isostere as a F NMR Label for the Peptide Backbone: Synthesis and Evaluation in Membrane-Bound PGLa and (KIGAKI).

Solid-state F NMR is a powerful method to study the interactions of biologically active peptides with membranes. So far, in labelled peptides, the F-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) are representatives of an α-helix and a β-sheet.

Incorporating a Monofluoroalkene into the Backbones of Short Peptides: Evaluating the Impact on Local Hydrophobicity.

The local hydrophobicity of an amino acid residue in a peptide sequence can be determined by measuring the hydrophobicity index (φ ) by reversed-phase (RP) HPLC. Herein, the impact on the local hydrophobicity of the replacement of an amide by a monofluoroalkene unit in short peptides is discussed. Monofluoroalkene-containing dipeptides and tripeptides were synthesized, as well as their natural parent compounds, and the hydrophobicity indexes of these short peptides and peptidomimetics were determined.

Recent progress in the racemic and enantioselective synthesis of monofluoroalkene-based dipeptide isosteres.

Monofluoroalkenes are fluorinated motifs that can be used to replace amide bonds. In order to be incorporated into peptides, it is normally necessary to first synthesize a dipeptide where the amide bond has been replaced with a monofluoroalkene. In that context, this review will present the racemic and enantioselective synthesis of monofluoroalkene-based dipeptide isosteres described since 2007.

Palladium-catalyzed synthesis of monofluoroalkenes from 3,3-difluoropropenes using dimethylmalonate and derivatives as nucleophiles.

The synthesis of monofluoroalkenes bearing a malonate or its derivatives at the β position is presented. The reaction can be performed with various 3,3-difluoropropenes. A preliminary result for an enantioselective variant is also reported.

Direct C-F bond formation using photoredox catalysis.

We have developed the first example of a photoredox catalytic method for the formation of carbon-fluorine (C-F) bonds. The mechanism has been studied using transient absorption spectroscopy and involves a key single-electron transfer from the (3)MLCT (triplet metal-to-ligand charge transfer) state of Ru(bpy)3(2+) to Selectfluor. Not only does this represent a new reaction for photoredox catalysis, but the mild reaction conditions and use of visible light also make it a practical improvement over previously developed UV-mediated decarboxylative fluorinations.