Insights into the Enantioselective Au(I)-Catalyzed Reactions between 2-Alkynyl Ketones and Naphthols using the TCDC Approach

The CPAPhosAuCl bifunctional complexes catalyse the enantioselective tandem cycloisomerization-nucleophilic addition reactions between 2-alkynylenones and naphthols, where naphthols behave mainly as O-nucleophiles. The inherent acidity of the catalysts induces then the isomerization of the O-addition- into the C-addition products with concomitant decrease of their enantiomeric excesses. In depth mechanistic studies have provided insights into these processes. Subsequently, the undesired racemization pathways could be suppressed by using substituted naphthols as nucleophiles, which delivered a large series of chiral bicyclic furanes in high enantioselectivities.