Transfer of Chirality in the Rhodium-Catalyzed Intramolecular Formal Hetero-[5 + 2] Cycloaddition of Vinyl Aziridines and Alkynes: Stereoselective Synthesis of Fused Azepine Derivatives

By
taking advantage of vinyl aziridines as a heteroatom-containing five-atom
component in rhodium-catalyzed intramolecular formal hetero-[5 + 2]
cycloaddition reactions with alkynes, a highly efficient method for
the synthesis of fused azepine derivatives at 30 °C was developed.
The reaction has broad substrate scope and tolerates a wide range
of functional groups. The chirality of vinyl aziridine-alkyne substrates
can be completely transferred to the cycloadducts, representing an
atom-economic and enantiospecific protocol for the construction of
fused 2,5-dihydroazepines for the first time.