Recent Advances in Asymmetric [1,2]-Stevens-Type Rearrangement via Metal Carbenes

Abstract

[1,2]-Stevens rearrangement is a widely used transformation in synthetic organic chemistry. However, the enantioselective versions are relatively limited and most of them rely on substrate-induced methodologies. In recent years, metal carbene chemistry has been extensively investigated, and the related asymmetric [1,2]-Stevens rearrangement experienced quick development by employing ylide intermediates generated from the reaction of metal carbenes with heteroatoms. This review summarizes the recent advances in asymmetric [1,2]-Stevens-type rearrangement via metal carbenes by presenting their product diversity, selectivity, and mechanistic rationale, which is organized based on the modes of chirality control.

Organocatalytic Enantioselective [1,2]-Stevens Rearrangement of Azetidinium Salts

“…[1,2]-Stevens rearrangements of cyclic ammonium ylides produce ring-expanded heterocycles. , Application of this transformation in alkaloid synthesis, however, is limited by the near total void of catalytic asymmetric methods . Syntheses employing this rearrangement provide racemic natural products, or require enantiopure quaternary ammonium salt substrates to access alkaloids as single enantiomers .…”