1. Decatungstate-photocatalysed C(sp3)-H azidation
Yen-Chu Lu, Shih-Chieh Kao, Julian G West Chem Commun (Camb). 2022 Apr 14;58(31):4869-4872.doi: 10.1039/d2cc00425a.
C-H Azidation is an increasingly important tool for bioconjugation, materials chemistry, and the synthesis of nitrogen-containing natural products. While several approaches have been developed, these often require exotic and energetic reagents, expensive photocatalysts, or both. Here we report a simple and general C-H azidation reaction using earth-abundant tetra-n-butylammonium decatungstate as a photocatalyst and commercial p-acetamidobenzenesulfonyl azide (p-ABSA) as the azide source. This system can azidate a variety of unactivated C(sp3)-H bonds in moderate to good yields and excellent turnover numbers. Preliminary mechanistic experiments implicate a radical mechanism proceeding VIA photo-hydrogen atom transfer (photo-HAT).
2. Azidation in the Difunctionalization of Olefins
Kai Wu, Yujie Liang, Ning Jiao Molecules. 2016 Mar 16;21(3):352.doi: 10.3390/molecules21030352.
Organic azides are key motifs in compounds of relevance to chemical biology, medicinal chemistry and materials science. In addition, they also serve as useful building blocks due to their remarkable reactivity. Therefore, the development of efficient protocols to synthesize these compounds is of great significance. This paper reviews the major applications and development of azidation in difunctionalization of olefins using azide reagents.
3. Cross-Correlated Motions in Azidolysozyme
Seyedeh Maryam Salehi, Markus Meuwly Molecules. 2022 Jan 27;27(3):839.doi: 10.3390/molecules27030839.
The changes in the local and global dynamics of azide-labelled lysozyme compared with that of the wild type protein are quantitatively assessed for all alanine residues along the polypeptide chain. Although attaching -N3 to alanine residues has been considered to be a minimally invasive change in the protein it is found that depending on the location of the alanine residue, the local and global changes in the dynamics differ. For Ala92, the change in the cross-correlated motions are minimal, whereas attaching -N3 to Ala90 leads to pronounced differences in the local and global correlations as quantified by the cross-correlation coefficients of the Cα atoms. We also demonstrate that the spectral region of the asymmetric azide stretch distinguishes between alanine attachment sites, whereas changes in the low frequency, far-infrared region are less characteristic.
