Modular Access to the Stereoisomers of Fused Bicyclic Azepines: Rhodium-Catalyzed Intramolecular Stereospecific Hetero-[5+2] Cycloaddition of Vinyl Aziridines and Alkenes

摘要

The first rhodium-catalyzed intramolecular hetero-[5+2] cycloaddition reaction of vinyl aziridines and alkenes was realized, wherein both internal and terminal alkenes were applicable. With this method, a variety of unique substituted chiral fused bicyclic azepines, bearing multiple contiguous stereogenic centers, were facilely accessed in a straightforward, high-yielding, and highly stereoselective manner under mild reaction conditions. Notably, the E/Z geometry of the C=C bonds in the vinyl aziridine-alkene substrates impact the cis/trans stereochemistry of the cycloadducts and up to six stereoisomers could be delivered.