In this issue, B. Xing et al. review rational design of nanogels for overcoming the biological barriers in various administration routes, and S. Sando et al. summarize the design of molecular NMR probes for hyperpolarized bioimaging. The Minireviews deal with a biological nanopore approach for single-molecule protein sequencing (Y.-T. Long et al.) and reproducibility in electroorganic synthesis (S. R. Waldvogel et al.).

In the original research section, I. Krossing et al. chase the Mond cation by synthesis and characterization of the homoleptic nickel tetracarbonyl cation and its tricarbonyl-nitrosyl analogue. Y. R. Chi et al. obtained access to allene-containing molecules via enantioselective reactions of azolium cumulenolate intermediates. T. Wang et al. succeeded in the enantiodivergent kinetic resolution of 1,1′-biaryl-2,2′-diols and amino alcohols by dipeptide-phosphonium salt catalysis (see picture). U. Alexiev et al. developed a dual fluorescence—spin label probe for visualization and quantification of target molecules in tissue by multiplexed FLIM-EPR spectroscopy.

• Angewandte Chemie 27/2021: Reproducibility,
  Angew. Chem. Int. Ed. 2020, 60 (27).