A conformationally restricted monofluorinated α-amino acid, (3-fluorobicyclo[1.1.1]pentyl)glycine (F-Bpg), was designed as a label for the structural analysis of membrane-bound peptides by solid-state F NMR spectroscopy. The compound was synthesized and validated as a F label for replacing natural aliphatic α-amino acids. Calculations suggested that F-Bpg is similar to Leu/Ile in terms of size and lipophilicity. The F NMR label was incorporated into the membrane-active antimicrobial peptide PGLa and provided information on the structure of the peptide in a lipid bilayer.

Syntheses of bicyclo[1.1.1]pentane‐derived azides and terminal alkynes – interesting substrates for click reactions – are described. With a few exceptions, these compounds were prepared in two or three steps starting from common synthetic intermediates – the corresponding carboxylic acids. The key step in the synthesis of 1‐azidobicyclo[1.1.1]pentanes is a copper‐catalysed diazo‐transfer reaction with imidazole‐1‐sulfonyl azide. The preparation of bicyclo[1.1.1]pentyl‐substituted alkynes relies on a Seyferth–Gilbert homologation with dimethyl 1‐diazo‐2‐oxopropylphosphonate (Ohira–Bestmann reagent). Both types of target compounds were found to be suitable substrates for click reactions, and thus they are promising building blocks for medicinal, combinatorial and bioconjugate chemistry. A practically important side result of this study was a multigram preparation of Boc‐monoprotected 1,3‐diaminobicyclo[1.1.1]pentane – a representative bicyclic conformationally restricted diamine derivative.

A convenient approach to 1,3-bifunctional sulfonyl fluorides, sulfonamides and sulfinates bearing a bicyclo-[1.1.1]pentane unit attached to the sulfur atom and (protected) amino or carboxyl group is described. The method relied on photochemical decomposition of Barton [1-hydroxypyridine-2(1H)-thione] esters of the corresponding carboxylic acids as [a] Taras

Differentiation of identical electrophilic functional groups (carboxylates) by a strategically placed internal nucleophile (an amino group) in cyclic precursors was used as a key general approach to functionalized azabicyclic scaffolds.

A conformationally restricted monofluorinated α‐amino acid, (3‐fluorobicyclo[1.1.1]pentyl)glycine (F‐Bpg), was designed as a label for the structural analysis of membrane‐bound peptides by solid‐state 19F NMR spectroscopy. The compound was synthesized and validated as a 19F label for replacing natural aliphatic α‐amino acids. Calculations suggested that F‐Bpg is similar to Leu/Ile in terms of size and lipophilicity. The 19F NMR label was incorporated into the membrane‐active antimicrobial peptide PGLa and provided information on the structure of the peptide in a lipid bilayer.

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