Gold-Catalyzed [3+2] Cycloaddltion/Hydrolytic Michael Addition/ Retro-Aldol Reactions of Propargylic Esters Tethered to Cyclohexadienomes

摘要

Functionalized cyclohexenones and cyclohexanones represent two recurring structural motifs found in many bioactive natural products. Synthetically, a very important approach for accessing these compounds is to take advantage of the oxidative de-aromatization/conjugate addition sequence using the corresponding phenolic precursors. In this context, a number of highly efficient catalysis methods have been established and can deliver the desired conjugate addition event with excellent reactivity and selectivity. However, these methods usually fail when a putative nucleophile contains a hard and sterically demanding quaternary carbon center.