Introducing 1,3-enyne functionalization by nitrene transfer reaction

In the context of carbon–nitrogen bond formation, metal-catalyzed nitrene transfer reactions constitute a powerful transformation. While many saturated and unsaturated substrates can be modified with this strategy, the incorporation of nitrene into enynes yet remains undescribed. Herein, we report the first example of this transformation, leading to the formation of propargyl aziridines or unsaturated sulfinamides, corresponding to the attack of a copper-nitrene intermediate onto the ene or yne sites. Density functional theory (DFT) studies have provided an explanation for this diverse reactivity, which is sustained on the interactions of the enyne substituent with the pyrazolyl rings of the trispyrazolylborate ancillary ligand of the catalyst.