Chiral Ylides: Cycloaddition and Catalysis

This lecture covers the synthesis and reactivity of chiral ylides, focusing on their application in [3+2] cycloaddition reactions and catalytic processes. Topics include the formation of phosphonium, sulfonium, ammonium, and sulfoxonium ylides, their role in building stereocenters, and their use in various cycloadditions. The lecture also discusses the catalytic formation of chiral sulfonium ylides and asymmetric cyclopropanation via chiral ammonium ylides. Additionally, it explores the [2,3] rearrangement of ammonium ylides and the hydrogen bond-mediated inversion of selectivity. Various mechanisms and models for selectivity in different reactions are presented.