Asymmetric [3 + 2] cycloaddition of donor–acceptor aziridines with aldehydes via carbon–carbon bond cleavage

Abstract

An enantioselective [3 + 2] annulation of donor–acceptor aziridines with aldehydes has been realized using a Nd(OTf)₃/N,N′-dioxide/LiNTf₂ catalyst system, providing various chiral cis-1,3-oxazolidines in moderate to good yields with high levels of stereocontrol. A relay catalytic process is proposed where LiNTf₂ promotes the formation of azomethine ylide intermediates, and a chiral Nd(III)–N,N′-dioxide complex accelerates the asymmetric cycloaddition.