A Rh(III)-Catalyzed Formal [4+1] Approach to Pyrrolidines from Unactivated Terminal Alkenes and Nitrene Sources

We have developed
a formal [4+1] approach to pyrrolidines from
readily available unactivated terminal alkenes as 4-carbon partners.
The reaction provides a rapid construction of various pyrrolidine
containing structures, especially for the diastereoselective synthesis
of spiro-pyrrolidines. Mechanistic investigation suggests a Rh­(III)-catalyzed
intermolecular aziridination of the alkene and subsequent acid-promoted
ring expansion for the pyrrolidine formation.