In this issue, R. Zou et al. review bimetallic materials derived from metal–organic frameworks for electrochemical energy storage and M. C. Willis et al. discuss nucleophiles in cross-coupling arylations. The Minireviews deal with precision conjugation to generate protein–polymer conjugates (X. Liu, W. Gao) and reversible magnesium electrochemistry (Z. Liang, C. Ban).

In the original research section, Y. Zhao et al. describe sequence-selective protection of peptides from proteolysis (see picture). K. Meyer et al. transformed cobalt diazo compounds from nitrilimide to isocyanoamide via a diazomethanediide fleeting intermediate. K. Qian et al. report nanoparticle-assisted cation adduction and fragmentation of small metabolites. E. J. Skellam et al. found that the biosynthesis of 6-hydroxymellein requires a collaborating polyketide synthase-like enzyme.

• Angewandte Chemie 20/2021: Protection,
  Angew. Chem. Int. Ed. 2020, 60 (20).