An electron-deficient amide is utilized as a directing group to functionalize nonactivated C(sp)-H bonds through radical 1,5-hydrogen abstraction. The γ-bromoamides formed are subsequently converted to γ-lactones under mild conditions. The method described is not limited to tertiary and secondary positions but also allows functionalization of primary nonactivated sp-hybridized positions in a one-pot sequence. In addition, the broad functional group tolerance renders this method suitable for the late-stage introduction of γ-lactones into complex carbon frameworks.

The site‐selective C−H oxidation of unactivated positions in aliphatic ammonium chains poses a tremendous synthetic challenge, for which a solution has not yet been found. Here, we report the preferential oxidation of the strongly deactivated C3/C4 positions of aliphatic ammonium substrates by employing a novel supramolecular catalyst. This chimeric catalyst was synthesized by linking the well‐explored catalytic moiety Fe(pdp) to an alkyl ammonium binding molecular tweezer. The results highlight the vast potential of overriding the intrinsic reactivity in chemical reactions by guiding catalysis using supramolecular host structures that enable a precise orientation of the substrates.

A molecular tweezer based on a glycoluril‐derived framework bearing four phosphate groups was synthesized and shown to be capable of binding organic amines in aqueous solution. This work reports the Ka values for 30 complexes of this molecular tweezer and amine guests, determined by means of 1H NMR titrations. Both the hydrophobic cavity and the phosphate groups contribute to the binding. Bulkier molecules and molecules bearing negatively charged groups like carboxylates in amino acids bind less tightly due to a steric clash and coulombic repulsion. The narrow cavity and the strong ionic interactions of the phosphate groups with ammonium guests favor binding of aliphatic diamines. These binding properties clearly distinguish this system from structurally related molecular clips and tweezers.

We synthesized two resorcin[4]arene scaffolds with four phosphate binding groups. The superior binding affinity to nanocrystal surfaces is demonstrated using solution NMR spectroscopy and exceeds that of single phosphonates.

Selective nanomolar binding of biological polyamines to a novel glycoluril-derived molecular tweezer is reported. The high selectivity over their biosynthetic precursor may be of interest, as elevated polyamine levels are linked to several diseases.