Stereochemistry-Smart Ketone Editing via Pd(II)/Pd(IV) Decarboxylative Rearrangement
A Nature study reveals a palladium(II)/Pd(IV)–catalyzed decarboxylative semi-pinacol rearrangement that converts β-hydroxy carboxylic acids into ketones through a concerted six-membered Pd(IV) chelate, enabling precise stereochemical control (migrating carbon preserves configuration while the α-carbon inverts) and high migrating-group selectivity for unsymmetrical ketones. The method applies broadly to cyclic and acyclic ketones and aldehydes, avoids hazardous diazo reagents, and is showcased in a concise total synthesis of rupestine D, highlighting its potential as a versatile carbon-skeleton-editing tool.