Divergent Asymmetric Synthesis of Polycyclic Compounds via Vinyl Triazenes

Vinyl triazenes were obtained by enantioselective [2+2] cycloaddition reactions of bicyclic alkenes with 1‐alkynyl triazenes in the presence of a RuII catalyst with a chiral cyclopentadienyl ligand. These triazenes serve as unique vinyl cation surrogates. Under acidic conditions, the triazene functionality can be replaced with a variety of groups, including halides, alkoxides, sulfoxides, amides, arenes, and heteroarenes, thus providing efficient access to a pool of chiral polycyclic compounds. In with the new, in with the Nu: 1‐Alkynyl triazenes and bicyclic alkenes underwent enantioselective [2+2] cycloaddition catalyzed by a chiral cyclopentadienyl RuII complex to give vinyl triazenes. The triazene functionality was readily replaced with a variety of nucleophiles, including halides, alkoxides, sulfoxides, amides, arenes, and heteroarenes, thus providing efficient access to a wide range of chiral polycyclic compounds.