Three-Component Cycloaddition To Synthesize Aziridines and 1,2,3-Triazolines

An efficient three-component cycloaddition of oxa­(aza)­bicyclic
alkenes/norbornene in the presence of NaN3 and arylsulfonyl
chlorides was developed, affording the corresponding aziridine products
in good yields (up to 82%) with moderate to good endo/exo selectivities (up to >99:1 endo/exo). Further studies showed that the cycloaddition
of oxa­(aza)­bicyclic alkenes in the presence of NaN3 and
chloroalkanes could afford the exo-cycloadduct 1,2,3-triazolines
in good to excellent yields (up to 95%). Compared with the existing
methodologies, the current protocol demands very simple and mild reaction
conditions and is a metal-free catalyzed reaction. In addition, a
plausible mechanism for the cycloaddition reaction was also proposed.