Modern organic chemistry has produced such a large array of intricately complex products that it is easy to forget the simple motifs that have eluded bulk synthesis. One such case is the diazoalkene, an unsaturated variant of the more common diazoalkanes. Consisting of three adjacent double bonds (C=C=N=N), this fragment is of particular interest as a precursor to reactive vinylidenes. Antoni et al. report the preparation of an N-heterocycle–substituted diazoalkene by oxidation of an olefinic precursor with nitrous oxide. The compound is stable in solid and solution states under inert atmosphere and reacts cleanly with isocyanides.
Nat. Chem. 13, 587 (2021).
